A chemical amplification positive resist composition comprising a polymeric mixture of a polyhydroxystyrene derivative having a Mw of 1000-500,000 and a copolymer of hydroxystyrene and (meth)acrylate having a Mw of 1000-500,000, as a base resin, has improved dry etching resistance, high sensitivity, high resolution, and process adaptability, and is suppressed in the slimming of pattern films after development with aqueous base.

This invention relates to a chemical amplification resist composition, especially of the positive acting type, having a high sensitivity and resolution, and suitable as a micropatterning material for VLSI fabrication.
While a number of recent efforts are being made to achieve a finer pattern rule in the drive for higher integration and operating speeds in LSI devices, deep-ultraviolet, EB, EUV and x-ray lithographic techniques are thought to hold particular promise as the next generation in microfabrication technology. Deep-UV lithography is capable of achieving a minimum feature size of 0.24 xcexcm or less, and can form patterns with sidewalls that are nearly perpendicular to the substrate, when a resist having low light absorption is used.
Recently developed acid-catalyzed chemically amplified positive resists, such as those described in JP-B 2-27660, JP-A 63-27829, U.S. Pat. No. 4,491,628 and U.S. Pat. No. 5,310,619, utilize a high-intensity KrF excimer laser as the deep-UV light source. These resists, with their excellent properties such as high sensitivity, high resolution, and good dry etching resistance, are especially promising for deep-UV lithography.
Such chemically amplified positive resists include two-component systems comprising a base polymer and a photoacid generator, and three-component systems comprising a base polymer, a photoacid generator, and a dissolution regulator having acid labile groups.
For example, JP-A 62-115440 describes a resist comprising poly-4-tert-butoxystyrene and a photoacid generator. JP-A 3-223858 describes a similar two-component resist comprising a resin bearing tert-butoxy groups within the molecule, in combination with a photoacid generator. JP-A 4-211258 describes a two-component resist which is comprised of polyhydroxystyrene bearing methyl, isopropyl, tert-butyl, tetrahydropyranyl, and trimethylsilyl groups, together with a photoacid generator. JP-A 6-100488 discloses a resist comprised of a polydihydroxystyrene derivative, such as poly[3,4-bis(2-tetrahydropyranyloxy)styrene], poly[3,4-bis(tert-butoxycarbonyloxy)styrene] or poly[3,5-bis(2-tetrahydropyranyloxy)styrene], and a photoacid generator. These resists, however, have the drawbacks of slimming of a pattern film after development with an aqueous base solution and poor resistance to dry etching.
Also known in the art are resist compositions using copolymers of hydroxystyrene with (meth)acrylate for achieving a higher transparency and improving the adhesion to the substrate as disclosed in JP-A 8-101509 and 8-146610. The resist compositions of this type suffer from low heat resistance, partial pattern collapse, and pattern shape footing.
An object of the invention is to provide a chemical amplification type resist composition which has a higher sensitivity, resolution, dry etching resistance and process adaptability than conventional resist compositions, and is improved in the slimming of a pattern film after development with an aqueous base solution.
The invention provides a chemical amplification type resist composition comprising a polymeric mixture of a polymer comprising recurring units of the general formula (1) and having a weight average molecular weight of 1,000 to 500,000 and a polymer comprising recurring units of the general formula (2) and having a weight average molecular weight of 1,000 to 500,000. The combined use of the polymers of formulas (1) and (2) gives an effective base resin for a chemical amplification positive resist composition. The chemical amplification positive resist composition comprising the polymeric mixture, a photoacid generator and an organic solvent has a high sensitivity, high resolution, dry etching resistance and process adaptability, and is improved in the slimming of a pattern film after development with an aqueous base solution. The composition is thus well suited for practical use and advantageously used in precise microfabrication, especially in VLSI manufacture.
Herein R is a hydroxyl group or a OR3 group, R1 is hydrogen or methyl, R2 is a straight, branched or cyclic alkyl group of 1 to 8 carbon atoms, R3 and R4 each are an acid labile group, R5 is methyl or ethyl, Z is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, x is 0 or a positive integer, y is a positive integer, satisfying x+yxe2x89xa65, m is 0 or a positive integer, n is a positive integer, satisfying m+nxe2x89xa65, p, q, r and s each are 0 or a positive number, satisfying p+q+r+s=1.
Herein R6, R7 and R8 each are hydrogen or methyl, R9 is methyl or ethyl, E is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, R10 is a straight, branched or cyclic alkyl group of 1 to 20 carbon atoms, which may contain an oxygen or sulfur atom, R11 is a tertiary alkyl group of 1 to 20 carbon atoms, k is 0 or a positive integer of up to 5, t and w each are a positive number, u and v each are 0 or a positive number, either one of u and v is not equal to 0, satisfying t+u+v+w=1.
When the polymers of formulas (1) and (2) are formulated together in a resist composition, they cooperate to give greater advantages than compensating for their shortcomings. More particularly, when only the polymer of formula (1) is used, the resulting resist composition has the advantages of high sensitivity and resolution, but the disadvantages of poor dry etching resistance and considerable slimming of a pattern film after development with an aqueous base solution. On the other hand, when the polymer of formula (2) is used alone, the resulting resist composition has the advantages of good dry etching resistance and relatively suppressed slimming of a pattern film after development with an aqueous base solution, but the disadvantages of low sensitivity and pattern shape footing.
In contrast, formulating both the polymers of formulas (1) and (2) with other resist components results in a chemical amplification positive resist composition which has a higher sensitivity, resolution, dry etching resistance and process adaptability than the single use of each polymer, and forms a pattern film which undergoes a relatively small reduction of its thickness after development with an aqueous base solution.
Polymer
The chemical amplification type resist composition of the invention is characterized by comprising a polymeric mixture of a polymer comprising recurring units of the general formula (1) and having a weight average molecular weight of 1,000 to 500,000 and a polymer comprising recurring units of the general formula (2) and having a weight average molecular weight of 1,000 to 500,000.
In formula (1), R is a hydroxyl group or a OR3 group, R1 is hydrogen or methyl, R2 is a straight, branched or cyclic alkyl group of 1 to 8 carbon atoms, R3 and R4 each are an acid labile group, R5 is methyl or ethyl, Z is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, x is 0 or a positive integer, y is a positive integer, satisfying x+yxe2x89xa65, m is 0 or a positive integer, n is a positive integer, satisfying m+nxe2x89xa65, p, q, r and s each are 0 or a positive number, satisfying p+q+r+s=1.
Examples of the straight, branched or cyclic alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl and cyclohexyl.
The acid labile groups represented by R3 and R4 are selected from a variety of such groups, preferably from among the groups of the following formulas (3) and (4), branched or cyclic, tertiary alkyl groups with 4 to 20 carbon atoms, trialkylsilyl groups whose alkyl groups each have 1 to 6 carbon atoms, and oxoalkyl groups of 4 to 20 carbon atoms. It is noted that the acid labile groups represented by R3 and R4 are different.
In formula (3), R12 and R13 are independently hydrogen or straight, branched or cyclic alkyl groups of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl and n-octyl. R14 is a monovalent hydrocarbon group of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may have a hetero atom (e.g., oxygen atom), for example, straight, branched or cyclic alkyl groups, and such groups in which some hydrogen atoms are replaced by hydroxyl, alkoxy, oxo, amino or alkylamino groups. Illustrative examples of the substituted alkyl groups are given below.
A pair of R12 and R13, a pair of R12 and R14, or a pair of R13 and R14, taken together, may form a ring. Each of R12, R13 and R14 is a straight or branched alkylene group of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, when they form a ring.
In formula (4), R15 and R16 are as illustrated for R12 and R13. The organic groups of 4 to 40 carbon atoms represented by R17 include straight, branched or cyclic alkyl groups of 4 to 40 carbon atoms, especially tertiary alkyl groups of 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, trialkylsilyl groups whose alkyl groups each have 1 to 6 carbon atoms, oxoalkyl groups of 4 to 20 carbon atoms, and groups of formula (3). Exemplary tertiary alkyl groups are tert-butyl, tert-amyl, 1,1-diethylpropyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-butylcyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 1-isopropylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. Exemplary trialkylsilyl groups include trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. Exemplary oxoalkyl groups include 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, and 5-methyl-2-oxooxoran-5-yl. The letter xe2x80x9caxe2x80x9d is an integer of 0 to 6.
Of the acid labile groups of formula (3), the straight or branched groups are exemplified below.
Of the acid labile groups of formula (3), illustrative examples of the cyclic groups include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl and 2-methyltetrahydropyran-2-yl.
Examples of the acid labile groups of formula (4) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl, tert-amyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, and 2-tetrahydrofuranyloxycarbonylmethyl groups.
Examples of the tertiary alkyl groups of 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms include tert-butyl, tert-amyl, tert-ethyl-3-pentyl and dimethylbenzyl as well as 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl, 1-isopropylcyclopentyl, 1-n-butylcyclopentyl, 1-sec-butylcyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 3-methyl-1-cyclopenten-3-yl, 3-ethyl-1-cyclopenten-3-yl, 3-methyl-1-cyclohexen-3-yl, and 3-ethyl-1-cyclohexen-3-yl groups.
Exemplary trialkylsilyl groups whose alkyl groups each have 1 to 6 carbon atoms are trimethylsilyl, triethylsilyl, and tert-butyldimethylsilyl.
Exemplary oxoalkyl groups of 4 to 20 carbon atoms are 3-oxocyclohexyl and groups of the following formulas.
In formula (1), p, q, r and s each are 0 or a positive number, especially p, q and r are positive numbers and s is 0 or a positive number, and they satisfy p+q+r+s=1, preferably 0 less than (q+r)/(p+q+r+s)xe2x89xa60.8, especially 0.07xe2x89xa6(q+r)/(p+q+r+s)xe2x89xa60.5, and 0.01xe2x89xa6s/(p+q+r+s)xe2x89xa60.1, especially 0.01xe2x89xa6s/(p+q+r+s)xe2x89xa60.05. If any one of p, q and r is equal to 0, there may result a reduced contrast of alkali dissolution rate and a poor resolution. If the proportion of q+r relative to the total is in excess of 0.8 or if the proportion of s relative to the total is in excess of 0.1, the polymer may become gel due to over crosslinking, lose solubility in alkali solution, induce film thickness changes, in-film stresses or bubbles upon alkali development, and become less adhesive to the substrate due to the shortage of hydrophilic groups. By properly selecting the values of p, q and r within the above-defined ranges, it becomes possible to control the size and configuration of a resist pattern as desired.
It is noted that the content of acid labile groups in the polymer has a substantial influence on the dissolution rate contrast of a resist film and governs the properties of the resist composition relating to the size and configuration of a resist pattern.
In the polymer comprising recurring units of formula (1), the acid labile groups represented by R3 and R4 are preferably those of formulas (3) and (4) while the recurring units may be units of one type or a combination of units of two or more types.
In formula (2), R6, R7 and R8 each are hydrogen or methyl, R9 is methyl or ethyl, E is a straight, branched or cyclic alkylene group of 1 to 10 carbon atoms, R10 is a straight, branched or cyclic alkyl group of 1 to 20 carbon atoms or a straight, branched or cyclic alkyl group of 1 to 20 carbon atoms which contains an oxygen or sulfur atom, R11 is a tertiary alkyl group of 1 to 20 carbon atoms, k is 0 or a positive integer of up to 5, t and w each are a positive number, u and v each are 0 or a positive number, either one of u and v is not equal to 0, satisfying t+u+v+w=1.
The acid labile group represented by R11 is selected from a variety of such groups, preferably from among the groups of the following formulas (5) and (6).
Herein, R18 is a methyl, ethyl, isopropyl, cyclohexyl, cyclopentyl, vinyl, acetyl, phenyl or cyano group. Letter b is an integer of 0 to 3.
The cyclic alkyl groups of formula (5) are preferably 5-membered rings. Examples include 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-vinylcyclopentyl, 1-acetylcyclopentyl, 1-phenylcyclopentyl, 1-cyanocyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 1-isopropylcyclohexyl, 1-vinylcyclohexyl, 1-acetylcyclohexyl, 1-phenylcyclohexyl, and 1-cyanocyclohexyl.
Herein, R19 is an isopropyl, cyclohexyl, cyclopentyl, vinyl, acetyl, phenyl or cyano group.
Examples of the group of formula (6) include 1-vinyldimethyl, 1-acetyldimethyl, 1-phenyldimethyl and 1-cyanodimethyl.
The alkyl groups represented by R10 include a variety of such groups, for example, cyclohexyl, cyclopentyl, norbornyl, isobornyl, 5-membered ring lactone, 6-membered ring lactone, and tetrahydrofuran groups as well as alkyl groups substituted with a carbonate, dioxoran, hydroxyethyl, and methoxymethyl group, though not limited thereto.
With the properties of the resist composition taken into account, t and w each are a positive number, u and v each are 0 or a positive number, either one of u and v is not equal to 0, and they preferably satisfy the ranges:
0 less than w/(t+u+v+w)xe2x89xa60.5, especially 0.2 less than w/(t+u+v+w)xe2x89xa60.4;
0xe2x89xa6v/(t+u+v+w)xe2x89xa60.2, especially 0.01 less than v/(t+u+v+w)xe2x89xa60.1; and
0xe2x89xa6u/(t+u+v+w)xe2x89xa60.05, especially 0 less than u/(t+u+v+w) less than 0.02.
If w is 0, indicating that the polymer of formula (2) does not contain the unit accompanied with w, there may result a reduced contrast of alkali dissolution rate and a poor resolution. If the proportion of t is too high, the alkali dissolution rate of unexposed areas may become too high. If both u and v are 0, there may result shortcomings such as poor resolution and poor dry etching resistance. By properly selecting the values of t, u, v and w within the above-defined ranges, it becomes possible to control the size and configuration of a resist pattern as desired.
The polymers of formulas (1) and (2) each should have a weight average molecular weight (Mw) of 1,000 to 500,000, and preferably 3,000 to 30,000. With too low a Mw, the resist composition becomes less resistant to heat. With too high a Mw, alkali dissolution is reduced and a footing phenomenon tends to arise after pattern formation.
In the polymers of the invention, if the polyhydroxystyrene and the (meth)acrylate copolymer have a wide molecular weight distribution or dispersity (Mw/Mn), it becomes difficult to design the number of crosslinks because of the presence of lower and higher molecular weight polymer components. This sometimes precludes consistent formulation of resist compositions to the same performance. The influences of molecular weight and dispersity become stronger as the pattern rule becomes finer. Therefore, the polyhydroxystyrene and the (meth)acrylate copolymer should preferably have a narrow dispersity (Mw/Mn) of 1.0 to 2.0, especially 1.0 to 1.5, in order to provide a resist composition suitable for micropatterning to a small feature size.
Resist Composition
The mixture of the polymers of formulas (1) and (2) is useful as a base resin in a chemical amplification, positive resist composition. The invention provides a chemical amplification, positive resist composition comprising the polymeric mixture as a base resin.
Specifically, a first embodiment of the invention is a chemical amplification, positive resist composition comprising (A) an organic solvent, (B) the polymeric mixture of the polymers of formulas (1) and (2) as a base resin, and (C) a photoacid generator.
A second embodiment of the invention is a chemical amplification, positive resist composition comprising (A) an organic solvent, (B) the polymeric mixture of the polymers of formulas (1) and (2) as a base resin, (C) a photoacid generator, and (D) a dissolution regulator.
In either embodiment, the resist composition may further include (E) a basic compound.
In the chemical amplification, positive resist composition, component (A) is an organic solvent. Illustrative, non-limiting, examples of the organic solvent include butyl acetate, amyl acetate, cyclohexyl acetate, 3-methoxybutyl acetate, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, cyclopentanone, 3-ethoxyethyl propionate, 3-ethoxymethyl propionate, 3-methoxymethyl propionate, methyl acetoacetate, ethyl acetoacetate, diacetone alcohol, methyl pyruvate, ethyl pyruvate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, 3-methyl-3-methoxybutanol, N-methylpyrrolidone, dimethylsulfoxide, xcex3-butyrolactone, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, methyl lactate, ethyl lactate, propyl lactate, and tetramethylene sulfone. Of these, the propylene glycol alkyl ether acetates and alkyl lactates are especially preferred. The solvents may be used alone or in admixture of two or more. An exemplary useful solvent mixture is a mixture of a propylene glycol alkyl ether acetate and an alkyl lactate. It is noted that the alkyl groups of the propylene glycol alkyl ether acetates are preferably those of 1 to 4 carbon atoms, for example, methyl, ethyl and propyl, with methyl and ethyl being especially preferred. Since the propylene glycol alkyl ether acetates include 1,2 and 1,3-substituted ones, each includes three isomers depending on the combination of substituted positions, which may be used alone or in admixture. It is also noted that the alkyl groups of the alkyl lactates are preferably those of 1 to 4 carbon atoms, for example, methyl, ethyl and propyl, with methyl and ethyl being especially preferred.
When the propylene glycol alkyl ether acetate is used as the solvent, it preferably accounts for at least 50% by weight of the entire solvent. Also when the alkyl lactate is used as the solvent, it preferably accounts for at least 50% by weight of the entire solvent. When a mixture of propylene glycol alkyl ether acetate and alkyl lactate is used as the solvent, that mixture preferably accounts for at least 50% by weight of the entire solvent. In this solvent mixture, it is further preferred that the propylene glycol alkyl ether acetate is 60 to 95% by weight and the alkyl lactate is 40 to 5% by weight. A lower proportion of the propylene glycol alkyl ether acetate would invite a problem of inefficient coating whereas a higher proportion thereof would provide insufficient dissolution and allow for particle and foreign matter formation. A lower proportion of the alkyl lactate would provide insufficient dissolution and cause the problem of many particles and foreign matter whereas a higher proportion thereof would lead to a composition which has a too high viscosity to apply and loses storage stability.
Usually the solvent is used in amounts of about 300 to 2,000 parts, preferably about 400 to 1,000 parts by weight per 100 parts by weight of the solids in the chemically amplified positive resist composition. The concentration is not limited to this range as long as film formation by existing methods is possible.
The photoacid generator (C) is a compound capable of generating an acid upon exposure to high energy radiation. Preferred photoacid generators are sulfonium salts, iodonium salts, sulfonyldiazomethanes, and N-sulfonyloxyimides. These photoacid generators are illustrated below while they may be used alone or in admixture of two or more.
Sulfonium salts are salts of sulfonium cations with sulfonates. Exemplary sulfonium cations include triphenylsulfonium, (4-tert-butoxyphenyl)diphenylsulfonium, bis(4-tert-butoxyphenyl)phenylsulfonium, tris(4-tert-butoxyphenyl)sulfonium, (3-tert-butoxyphenyl)diphenylsulfonium, bis(3-tert-butoxyphenyl)phenylsulfonium, tris(3-tert-butoxyphenyl)sulfonium, (3,4-di-tert-butoxyphenyl)diphenylsulfonium, bis(3,4-di-tert-butoxyphenyl)phenylsulfonium, tris(3,4-di-tert-butoxyphenyl)sulfonium, diphenyl(4-thiophenoxyphenyl)sulfonium, (4-tert-butoxycarbonylmethyloxyphenyl)diphenylsulfonium, tris(4-tert-butoxycarbonylmethyloxyphenyl)sulfonium, (4-tert-butoxyphenyl)bis(4-dimethylaminophenyl)sulfonium, tris(4-dimethylaminophenyl)sulfonium, 2-naphthyldiphenylsulfonium, dimethyl-2-naphthylsulfonium, 4-hydroxyphenyldimethylsulfonium, 4-methoxyphenyldimethylsulfonium, trimethylsulfonium, 2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium, and tribenzylsulfonium. Exemplary sulfonates include trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, 4,4-toluenesulfonyloxy-benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate. Sulfonium salts based on combination of the foregoing examples are included.
Iodinium salts are salts of iodonium cations with sulfonates. Exemplary iodinium cations are aryliodonium cations including diphenyliodinium, bis(4-tert-butylphenyl)iodonium, 4-tert-butoxyphenylphenyliodonium, and 4-methoxyphenylphenyliodonium. Exemplary sulfonates include trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, 4,4-toluenesulfonyloxy-benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate. Iodonium salts based on combination of the foregoing examples are included.
Exemplary sulfonyldiazomethane compounds include bissulfonyldiazomethane compounds and sulfonylcarbonyldiazomethane compounds such as bis(ethylsulfonyl)diazomethane, bis(1-methylpropylsulfonyl)diazomethane, bis(2-methylpropylsulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(perfluoroisopropylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(4-methylphenylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, bis(2-naphthylsulfonyl)diazomethane, 4-methylphenylsulfonylbenzoyldiazomethane, tert-butylcarbonyl-4-methylphenylsulfonyldiazomethane, 2-naphthylsulfonylbenzoyldiazomethane, 4-methylphenylsulfonyl-2-naphthoyldiazomethane, methylsulfonylbenzoyldiazomethane, and tert-butoxycarbonyl-4-methylphenylsulfonyldiazomethane.
N-sulfonyloxyimide photoacid generators include combinations of imide skeletons with sulfonates. Exemplary imide skeletons are succinimide, naphthalene dicarboxylic acid imide, phthalimide, cyclohexyldicarboxylic acid imide, 5-norbornene-2,3-dicarboxylic acid imide, and 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid imide. Exemplary sulfonates include trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate.
Benzoinsulfonate photoacid generators include benzoin tosylate, benzoin mesylate, and benzoin butanesulfonate.
Pyrogallol trisulfonate photoacid generators include pyrogallol, fluoroglycine, catechol, resorcinol, hydroquinone, in which all the hydroxyl groups are replaced by trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate.
Nitrobenzyl sulfonate photoacid generators include 2,4-dinitrobenzyl sulfonate, 2-nitrobenzyl sulfonate, and 2,6-dinitrobenzyl sulfonate, with exemplary sulfonates including trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate. Also useful are analogous nitrobenzyl sulfonate compounds in which the nitro group on the benzyl side is replaced by a trifluoromethyl group.
Sulfone photoacid generators include bis(phenylsulfonyl)methane, bis(4-methylphenylsulfonyl)methane, bis(2-naphthylsulfonyl)methane, 2,2-bis(phenylsulfonyl)propane, 2,2-bis(4-methylphenylsulfonyl)propane, 2,2-bis(2-naphthylsulfonyl)propane, 2-methyl-2-(p-toluenesulfonyl)propiophenone, 2-cyclohexylcarbonyl-2-(p-toluenesulfonyl)propane, and 2,4-dimethyl-2-(p-toluenesulfonyl)pentan-3-one.
Photoacid generators in the form of glyoxime derivatives include bis-o-(p-toluenesulfonyl)-xcex1-dimethylglyoxime, bis-o-(p-toluenesulfonyl)-xcex1-diphenylglyoxime, bis-o-(p-toluenesulfonyl)-xcex1-dicyclohexylglyoxime, bis-o-(p-toluenesulfonyl)-2,3-pentanedioneglyoxime, bis-o-(p-toluenesulfonyl)-2-methyl-3,4-pentanedioneglyoxime, bis-o-(n-butanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(n-butanesulfonyl)-xcex1-diphenylglyoxime, bis-o-(n-butanesulfonyl)-xcex1-dicyclohexylglyoxime, bis-o-(n-butanesulfonyl)-2,3-pentanedioneglyoxime, bis-o-(n-butanesulfonyl)-2-methyl-3,4-pentanedioneglyoxime, bis-o-(methanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(trifluoromethanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(1,1,1-trifluoroethanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(tert-butanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(perfluorooctanesulfonyl)-xcex1-dimethylglyoxime, bis-o-(cyclohexylsulfonyl)-xcex1-dimethylglyoxime, bis-o-(benzenesulfonyl)-xcex1-dimethylglyoxime, bis-o-(p-fluorobenzenesulfonyl)-xcex1-dimethylglyoxime, bis-o-(p-tert-butylbenzenesulfonyl)-xcex1-dimethylglyoxime, bis-o-(xylenesulfonyl)-xcex1-dimethylglyoxime, and bis-o-(camphorsulfonyl)-xcex1-dimethylglyoxime.
Of these photoacid generators, the sulfonium salts, bissulfonyldiazomethane compounds, and N-sulfonyloxyimide compounds are preferred.
While the anion of the optimum acid to be generated differs depending on the ease of scission of acid labile groups introduced in the polymer, an anion which is nonvolatile and not extremely diffusive is generally chosen. The preferred anions include benzenesulfonic acid anions, toluenesulfonic acid anions, 4,4-toluenesulfonyloxybenzenesulfonic acid anions, pentafluorobenzenesulfonic acid anions, 2,2,2-trifluoroethanesulfonic acid anions, nonafluorobutanesulfonic acid anions, heptadecafluorooctanesulfonic acid anions, and camphorsulfonic acid anions.
In the chemically amplified positive resist composition, an appropriate amount of the photoacid generator (C) is 0 to 20 parts, and especially 1 to 10 parts by weight per 100 parts by weight of the solids in the composition. The photoacid generators may be used alone or in admixture of two or more. The transmittance of the resist film can be controlled by using a photoacid generator having a low transmittance at the exposure wavelength and adjusting the amount of the photoacid generator added.
The dissolution regulator (D) is a compound having on the molecule at least two phenolic hydroxyl groups, in which an average of from 10 to 100 mol % of all the hydrogen atoms on the phenolic hydroxyl groups are replaced with acid labile groups. The compound has a weight average molecular weight within the range of 100 to 1,000, and preferably 150 to 800. The dissolution regulator may be formulated in an amount of 0 to 50 parts, preferably 5 to 50 parts, and more preferably 10 to 30 parts by weight, per 100 parts by weight of the base resin, and may be used singly or as a mixture of two or more thereof. Less amounts of the dissolution regulator may fail to yield an improved resolution, whereas too much amounts would lead to slimming of the patterned film, and thus a decline in resolution.
Illustrative, non-limiting, examples of the dissolution regulator (D) which are useful herein include
bis(4-(2xe2x80x2-tetrahydropyranyloxy)phenyl)methane,
bis(4-(2xe2x80x2-tetrahydrofuranyloxy)phenyl)methane,
bis(4-tert-butoxyphenyl)methane,
bis(4-tert-butoxycarbonyloxyphenyl)methane,
bis(4-tert-butoxycarbonylmethyloxyphenyl)methane,
bis(4-(1xe2x80x2-ethoxyethoxy)phenyl)methane,
bis(4-(1xe2x80x2-ethoxypropyloxy)phenyl)methane,
2,2-bis(4xe2x80x2-(2xe2x80x3-tetrahydropyranyloxy))propane,
2,2-bis(4xe2x80x2-(2xe2x80x3-tetrahydrofuranyloxy)phenyl)propane,
2,2-bis(4xe2x80x2-tert-butoxyphenyl)propane,
2,2-bis(4xe2x80x2-tert-butoxycarbonyloxyphenyl)propane,
2,2-bis(4-tert-butoxycarbonylmethyloxyphenyl)propane,
2,2-bis(4xe2x80x2-(1xe2x80x3-ethoxyethoxy)phenyl)propane,
2,2-bis(4xe2x80x2-(1xe2x80x3-ethoxypropyloxy)phenyl)propane,
tert-butyl 4,4-bis(4xe2x80x2-(2xe2x80x3-tetrahydropyranyloxy)phenyl)valerate,
tert-butyl 4,4-bis(4xe2x80x2-(2xe2x80x3-tetrahydrofuranyloxy)phenyl)valerate,
tert-butyl 4,4-bis(4xe2x80x2-tert-butoxyphenyl)valerate,
tert-butyl 4,4-bis(4-tert-butoxycarbonyloxyphenyl)valerate,
tert-butyl 4,4-bis(4xe2x80x2-tert-butoxycarbonylmethyloxyphenyl)valerate,
tert-butyl 4,4-bis(4xe2x80x2-(1xe2x80x3-ethoxyethoxy)phenyl)valerate,
tert-butyl 4,4-bis(4xe2x80x2-(1xe2x80x3-ethoxypropyloxy)phenyl)valerate,
tris(4-(2xe2x80x2-tetrahydropyranyloxy)phenyl)methane,
tris(4-(2xe2x80x2-tetrahydrofuranyloxy)phenyl)methane,
tris(4-tert-butoxyphenyl)methane,
tris(4-tert-butoxycarbonyloxyphenyl)methane,
tris(4-tert-butoxycarbonyloxymethylphenyl)methane,
tris(4-(1xe2x80x2-ethoxyethoxy)phenyl)methane,
tris(4-(1xe2x80x2-ethoxypropyloxy)phenyl)methane,
1,1,2-tris(4xe2x80x2-(2xe2x80x3-tetrahydropyranyloxy)phenyl)ethane,
1,1,2-tris(4xe2x80x2-(2xe2x80x3-tetrahydrofuranyloxy)phenyl)ethane,
1,1,2-tris(4xe2x80x2-tert-butoxyphenyl)ethane,
1,1,2-tris(4xe2x80x2-tert-butoxycarbonyloxyphenyl)ethane,
1,1,2-tris(4xe2x80x2-tert-butoxycarbonylmethyloxyphenyl)ethane,
1,1,2-tris(4xe2x80x2-(1xe2x80x2-ethoxyethoxy)phenyl)ethane, and
1,1,2-tris(4xe2x80x2-(1xe2x80x2-ethoxypropyloxy)phenyl)ethane.
The basic compound (E) is preferably a compound capable of suppressing the rate of diffusion when the acid generated by the photoacid generator diffuses within the resist film. The inclusion of this type of basic compound holds down the rate of acid diffusion within the resist film, resulting in better resolution. In addition, it suppresses changes in sensitivity following exposure and reduces substrate and environment dependence, as well as improving the exposure latitude and the pattern profile.
Examples of basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, carboxyl group-bearing nitrogenous compounds, sulfonyl group-bearing nitrogenous compounds, hydroxyl group-bearing nitrogenous compounds, hydroxyphenyl group-bearing nitrogenous compounds, alcoholic nitrogenous compounds, amide derivatives, and imide derivatives.
Examples of suitable primary aliphatic amines include ammonia, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, cyclopentylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, and tetraethylenepentamine. Examples of suitable secondary aliphatic amines include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diusobutylamine, di-sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N,N-dimethylmethylenediamine, N,N-dimethylethylenediamine, and N,N-dimethyltetraethylenepentamine. Examples of suitable tertiary aliphatic amines include trimethylamine, triethylamine, tri-n-propylamine, truisopropylamine, tri-n-butylamine, truisobutylamine, tri-sec-butylamine, tripentylamine, tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tridodecylamine, tricetylamine, N,N,Nxe2x80x2,Nxe2x80x2-tetramethylmethylenediamine, N,N,Nxe2x80x2,Nxe2x80x2-tetramethylethylenediamine, and N,N,Nxe2x80x2,Nxe2x80x2-tetramethyltetraethylenepentamine.
Examples of suitable mixed amines include dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, and benzyldimethylamine. Examples of suitable aromatic and heterocyclic amines include aniline derivatives (e.g., aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N,N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, and N,N-dimethyltoluidine), diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (e.g., pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, and N-methylpyrrole), oxazole derivatives (e.g., oxazole and isooxazole), thiazole derivatives (e.g., thiazole and isothiazole), imidazole derivatives (e.g., imidazole, 4-methylimidazole, and 4-methyl-2-phenylimidazole), pyrazole derivatives, furazan derivatives, pyrroline derivatives (e.g., pyrroline and 2-methyl-1-pyrroline), pyrrolidine derivatives (e.g., pyrrolidine, N-methylpyrrolidine, pyrrolidinone, and N-methylpyrrolidone), imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (e.g., pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridine, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2-(1-ethylpropyl)pyridine, aminopyridine, and dimethylaminopyridine), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (e.g., quinoline and 3-quinolinecarbonitrile), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, and uridine derivatives.
Examples of suitable carboxyl group-bearing nitrogenous compounds include aminobenzoic acid, indolecarboxylic acid, and amino acid derivatives (e.g. nicotinic acid, alanine, alginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, and methoxyalanine). Examples of suitable sulfonyl group-bearing nitrogenous compounds include 3-pyridinesulfonic acid and pyridinium p-toluenesulfonate. Examples of suitable hydroxyl group-bearing nitrogenous compounds, hydroxyphenyl group-bearing nitrogenous compounds, and alcoholic nitrogenous compounds include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N,N-diethylethanolamine, truisopropanolamine, 2,2xe2x80x2-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4-(2-hydroxyethyl)morpholine, 2-(2-hydroxyethyl)pyridine, 1-(2-hydroxyethyl)piperazine, 1-[2-(2-hydroxyethoxy)ethyl]-piperazine, piperidine ethanol, 1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyjulolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2-pyrrolidine ethanol, 1-aziridine ethanol, N-(2-hydroxyethyl)phthalimide, and N-(2-hydroxyethyl)isonicotinamide. Examples of suitable amide derivatives include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, and benzamide. Suitable imide derivatives include phthalimide, succinimide, and maleimide.
Also useful are substituted ones of the hydroxyl group-bearing nitrogenous compounds in which some or all of the hydrogen atoms of hydroxyl groups are replaced by methyl, ethyl, methoxymethyl, methoxyethoxymethyl, acetyl, or ethoxyethyl groups. Preferred are methyl-, acetyl-, methoxymethyl- and methoxyethoxymethyl-substituted compounds of ethanolamine, diethanolamine and triethanolamine. Examples include tris(2-methoxyethyl)amine, tris(2-ethoxyethyl)amine, tris(2-acetoxyethyl)amine, tris(2-(methoxymethoxy)ethylyamine, tris{2-(methoxyethoxy)ethyl}amine, tris[2-{(2-methoxyethoxy)methoxy}ethyl]amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, and tris[2-{(2-hydroxyethoxy)ethoxy}ethyl]amine.
The basic compounds may be used alone or in admixture of two or more. The basic compound is preferably formulated in an amount of 0 to 2 parts, and especially 0.01 to 1 part by weight, per 100 parts by weight of the solids in the resist composition. The use of more than 2 parts of the basis compound would result in too low a sensitivity.
In the resist composition, a surfactant may be added for improving coating characteristics.
Illustrative, non-limiting, examples of the surfactant include nonionic surfactants, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, and sorbitan monostearate, and polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorochemical surfactants such as EFTOP EF301, EF303 and EF352 (Tohkem Products K.K.), Megaface F171, F172 and F173 (Dai-Nippon Ink and Chemicals K.K.), Florade FC430 and FC431 (Sumitomo 3M K.K.), Aashiguard AG710, Surflon S-381, S-382, SC101, SC102, SC103, SC104, SC105, SC106, Surfynol E1004, KH-10, KH-20, KH-30 and KH-40 (Asahi Glass K.K.); organosiloxane polymers KP341, X-70-092 and X-70-093 (Shin-Etsu Chemical Co., Ltd.), acrylic acid or methacrylic acid Polyflow No. 75 and No. 95 (Kyoeisha Ushi Kagaku Kogyo K.K.). Inter alia, FC430, Surflon S-381, Surfynol E1004, KH-20 and KH-30 are preferred. These surfactants may be used alone or in admixture.
In the resist composition, the surfactant is preferably formulated in an amount of up to 2 parts, and especially up to 1 part by weight, per 100 parts by weight of the solids in the resist composition.
For the microfabrication of integrated circuits, any well-known lithography may be used to form a resist pattern from the chemical amplification, positive working, resist composition comprising (A) an organic solvent, (B) a polymeric mixture of the polymers of formulas (1) and (2), and (C) a photoacid generator, as illustrated above, according to the invention.
The composition is applied onto a substrate (e.g., Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflecting film, etc.) by a suitable coating technique such as spin coating, roll coating, flow coating, dip coating, spray coating or doctor coating. The coating is prebaked on a hot plate at a temperature of 60 to 150xc2x0 C. for about 1 to 10 minutes, preferably 80 to 120xc2x0 C. for 1 to 5 minutes. The resulting resist film is generally 0.1 to 2.0 xcexcm thick. With a mask having a desired pattern placed above the resist film, the resist film is then exposed to actinic radiation, preferably having an exposure wavelength of up to 300 nm, such as UV, deep-UV, electron beams, x-rays, excimer laser light, xcex3-rays and synchrotron radiation in an exposure dose of about 1 to 200 mJ/cm2, preferably about 10 to 100 mJ/cm2. The film is further baked on a hot plate at 60 to 150xc2x0 C. for 1 to 5 minutes, preferably 80 to 120xc2x0 C. for 1 to 3 minutes (post-exposure baking=PEB).
Thereafter the resist film is developed with a developer in the form of an aqueous base solution, for example, 0.1 to 5%, preferably 2 to 3% aqueous solution of tetramethylammonium hydroxide (TMAH) for 0.1 to 3 minutes, preferably 0.5 to 2 minutes by conventional techniques such as dipping, puddling or spraying. In this way, a desired resist pattern is formed on the substrate. It is appreciated that the resist composition of the invention is best suited for micro-patterning using such actinic radiation as deep UV with a wavelength of 254 to 193 nm, vacuum UV with a wavelength of 157 nm, electron beams, x-rays, excimer laser light, xcex3-rays and synchrotron radiation. With any of the above-described parameters outside the above-described range, the process may sometimes fail to produce the desired pattern.

Chemical amplification resist compositions


A light emitting device that provides white light of various color temperatures by using a double-sided light emitting element, a light emitting system comprising the same, and a method of fabricating thereof are provided. The light emitting device includes a double-sided light emitting element including a first light emitting element on one side of a substrate and emits light having a first wavelength and a second light emitting element on the other side of the substrate and emits light having a second wavelength, wherein the first wavelength and the second wavelength are different each other, a first variable resistor coupled to the first light emitting element and adjusting a first driving power applied to the first light emitting element, and a second variable resistor coupled to the second light emitting element and adjusting a second driving power applied to the second light emitting element.

1. Field
Exemplary embodiments relate to a light emitting device, a light emitting system comprising the same, and a method of fabricating thereof. More particularly, the exemplary embodiments relate to a light emitting device that provides white light of various color temperatures by using a double-sided light emitting element, a light emitting system comprising the same, and a method of fabricating thereof.
2. Description of Related Art
A light emitting element such as LED (Light Emitting Diode) emits light by a combination of electrons and holes. A light emitting element can require little power consumption, and enjoy a long life span. Further, it can be installed in a limited space. Further, a light emitting element has strong characteristics against vibration.
Depending on the fabrication methods, a light emitting device can generate light of various wavelengths, for example, blue light, UV light, and white light wavelengths.
To generate white light, yellow phosphor can spread over a light emitting element that emits light with a wavelength such as blue light to generate bluish white light. Also, yellow phosphor and red phosphor can spread over a blue light emitting element and a light emitting device that generates reddish white light can thus be provided. However, such cases can have limitations of providing various color temperatures.

Light emitting device, light emitting system comprising the same, and method of fabricating thereof


A snubber circuit for a chopper circuit has at least one chopper transistor with terminals connected to a first line and to a second line, the first line being at a power supply potential and the second line being at ground potential. The snubber circuit has a capacitive element and a charging diode for charging the capacitive element. The charging diode and the capacitive element are connected in series to each other and together they are connected in parallel with the chopper transistor. The snubber circuit has an inductive element having a first end connected to a connection point situated between the charging diode and the capacitive element, and a second end connected to one of the lines.

An inverter generally comprises a chopper circuit having pairs in chopper transistors that are connected to each other in series. These pairs of chopper transistors are connected in parallel between a first line and to a second line. The first line is at a power supply potential and the second line is at ground potential. Such inverters are subjected to thermal stresses and they are subjected to surge voltages and to fast variations in voltage that stress their components.
In order to remedy those drawbacks, it is known to associate a chopper circuit with a snubber circuit that comprises a capacitive element and a charging diode for charging the capacitive element, which capacitive element and charging diode are connected to each other in series and together they are connected in parallel with one of the chopper transistors in each pair of chopper transistors. The snubber circuit also includes a resistor having a first end connected to a connection point situated between the charging diode and the capacitive element, and a second end connected to the first line. Thus, when the chopper transistor switches from its conductive stage to its non-conductive state, the energy loss resulting from switching is recovered via the diode in the capacitive element that enables a zero voltage to be maintained across the terminals of the transistor. When the chopper transistor is controlled to switch to its conductive state, the energy stored in the capacitive element is dissipated in the resistor. A chopper circuit fitted with such a snubber circuit thus presents poor efficiency.

Active damping circuit for electric chopper circuit


In a satellite communications system comprising a plurality of access units X communicating with a satellite S on an up-link U and a broadcast downlink B and a plurality of gateways E to and from a network N, wherein each gateway E receives from the satellite S transmissions communicated thereto by the access units X and intended for destinations in the network N, a method of routing transmissions including a gateway E concluding that a transmission received should follow an alternative route via one of the other gateways E, sending an alternative route message to the satellite S which forwards the message using the broadcast downlink B to a plurality of the source gateways E in the system.

The invention relates to a method of routing traffic in satellite communications systems. The invention also relates to access units and gateways for such systems.
A communications system such as the Internet comprises a multitude of networks which are inter-connected by gateways. For instance, a local area network, which could comprise all the workstations in one company, may be connected by a gateway to a wide area network. Information is distributed around the Internet from sources, for example, hosts, to destinations, for example workstations, and vice versa, in the form of datagrams. The datagrams include data, which is information to be transmitted from sources to destinations, and destination information, that is, an address. The most common form of gateways are three layer gateways (or routers) which route datagrams, having assessed the destination information, in accordance with their knowledge of the organisation of the network to which they are connected.
Most networks have an appointed default gateway through which all traffic is routed. There may be other gateways on the network, and traffic destined for certain locations within the network may be more appropriately routed through one of these other gateways. When the default gateway receives a datagram for which it considers, by assessment of the destination information, that another one of the gateways may be more appropriate, it redirects the datagram.
When communications between networks are performed via satellite, and access units route traffic to and from a source to the satellite, redirecting a datagram may involve sending it over the satellite system""s links, which consumes satellite resources and introduces a delay into the transmission of the datagram. To overcome these problems, when a gateway receives from a satellite a datagram for which it considers that an alternative gateway unit may be more appropriate, it sends an internet control message protocol (ICMP) redirect message to the source of the datagram, suggesting that the datagram be sent directly to the alternative gateway, thereby cutting out the unnecessary additional step for all future transmissions.
In a system having a satellite link between networks, there may be a large number of sources, which means that there are potentially a large number of ICMP redirect messages passing around the system at any one time, which in turn may lead to congestion. Alternatively, each access unit may operate with routing protocols, but this may introduce huge complexity and does not reduce the amount of information carried over the satellite links.
In a local area network, sending a redirect message for future reference to all sources is not considered feasible because it entails extra processsing on the part of each source.
The object of the invention is to provide a method of efficiently routing transmissions in a satellite communications system which minimises the amount of control information in circulation.
According to a first aspect of the present invention there is provided a method of routing transmissions in a satellite communications system comprising a plurality of access units communicating with a satellite on an up-link and a broadcast downlink and a plurality of gateways to and from a network, each gateway receiving from the satellite transmissions communicated thereto by the access units and intended for destinations in the network, the method including a gateway concluding that a transmission received should follow an alternative route via one of the other gateways, sending an alternative route message to the satellite which forwards the message using the broadcast downlink to a plurality of access units in the system.
The invention takes advantage of the inherent broadcast capability of the satellite by disseminating the redirect message to a large number of access units in the system, thereby seeking to reduce future misdirected transmissions, and to optimise use of the satellite""s resources, with the minimum amount of control traffic. A satellite system is better adapted to utilise a method that is not feasible in a local area network, that is, disseminating an ICMP redirect message to a large number of sources, because the access units in a satellite system tend to be routers rather than simple hosts, and the routers devote part of their processing power and memory to routing. In addition, the resources of a satellite system are a more costly commodity than the resources of a local network, and the cost consequences of not optimising routing in a satellite system are more significant than in not optimising routing in a local area network.
Preferably, a transmission contains destination information and the gateway concludes that the transmission could follow an alternative route from the destination information and from its knowledge of the organisation of the network.
Further preferably, the system comprises the Internet and the transmission comprises a datagram including destination information and data.
A multicast address may be used to carry the alternative route message, so that access units may identify it and possibly discard it when overloaded with traffic.
The up-link may be a common up-link for all of the access units.
According to a second aspect of the present invention there is provided a gateway in a satellite communications system comprising a plurality of access units communicating with a satellite on an up-link and a broad downlink and a plurality of gateways to and from a network, each gateway receiving from the satellite transmissions communicated thereto by the access units and intended for destinations in the network, at least one gateway having means which, in response to receiving a transmission which it concludes should follow an alternative route via one of the other gateways, sends an alternative route message to the satellite for forwarding using the broadcast downlink to a plurality of the access units in the system.
According to a third aspect of the present invention there is provided an access unit in a satellite communications system comprising a plurality of access units communicating with a satellite on an up-link and a broadcast downlink and a plurality of gateways to and from a network, each access unit sending to the satellite transmissions intended for destinations in the network, which access units have means for an alternative route message forwarded by the satellite from a gateways to all access units on the broadcast downlink and means for routing transmissions according to the alternative route message.


Current sensor according to the compensation principle, in which the magnetic field produced by a primary winding (1) through which the current to be measured flows is compensated by the compensation current in a secondary winding (6), and in which for the controlling of the compensation current at least one sensor (3) that is influenced by the magnetic field acquires deviations from the zero current and supplies this measurement value to a driver circuit (5) for the production of the compensation current, whereby at the output of the driver circuit (5) the secondary winding (6) is connected in series to a terminating resistance (7), a voltage (Ua) that is proportional to the current to be measured is present at the terminating resistance (7), two amplifiers (5a,5b) in a bridge circuit, which are controlled by the measurement value and which supply output signals in phase opposition to one another, are used as a driver circuit (5), and the series circuit of the secondary winding (6) and terminating resistance (7) is connected between the outputs of the amplifiers.

The present invention relates to a current sensor according to the compensation principle, in which the magnetic field produced by a primary winding through which the current to be measured flows is compensated by the compensation current in a secondary winding, and in which for the controlling of the compensation current at least one sensor that is influenced by the magnetic field acquires deviations from the zero current and supplies this measurement value to a driver circuit for the production of the compensation current, whereby at the output of the driver circuit the secondary winding is connected in series to a terminating resistance, and a voltage that is proportional to the current to be measured is present at the terminating resistance.
A current sensor of this type according to the compensation principle is for example known from European Reference EP 356 248 and from European Reference EP 691 544, and is shown in FIG. 5 of the drawing. The current i.sub.1 that is to be measured thereby flows through the primary winding 1 of a current transformer, which for example comprises a magnet core 2 as well as a sensor 3 that measures the magnetic flux in the magnet core 2.
The sensor 3 consists for example of a transformer driven to saturation, with a rectangular magnetization characteristic. The output voltage of the sensor 3 is processed in a subsequently connected evaluation circuit 4; a driver circuit 5 is in turn connected downstream therefrom. The output of the driver circuit 5 is connected with a reference potential G via the secondary winding 6 of the current transformer and a terminating resistance 7.
The current to be measured now produces, via the primary winding 1, a magnetic flux in the magnet core 2, which flux is acquired by the sensor 3. The evaluation circuit 4 connected after the sensor 3 supplies a signal--which is dependent on the magnitude and direction of the magnetic field in the magnet core 2--to the driver circuit 5, which signal drives a compensation current i.sub.2 through the secondary winding 6. The compensation current i.sub.2 is oriented in such a way that its magnetic field compensates the magnetic flux in the magnet core 2. The current in the secondary winding 6 is altered by the sensor 3 in connection with the evaluation circuit 4, the driver circuit 5, and the secondary winding 6 until the magnetic field in the magnet core 2 goes to zero. The current i.sub.2 in the secondary winding 6 is thereby a measure for the momentary value of the current i.sub.1 to be measured in the primary winding 1, whereby both direct and alternating currents can be acquired. In addition, the current i.sub.2 flows via a terminating resistance 7 at which the output voltage Ua of the current sensor falls off, which output voltage thereby corresponds in magnitude and phase position to the current i.sub.1 to be measured in the primary winding 1.
The maximum measurable current i.sub.1max of the compensation current sensor is thereby: EQU i.sub.1max =w.sub.2.multidot.(U.sub.V -U.sub.B)/R.sub.1 +R.sub.a),
whereby w.sub.2 is equal to the number of secondary windings, U.sub.V is equal to the supply voltage, U.sub.B is equal to the voltage drop in the driver stage 5, R.sub.i is equal to the internal resistance of the secondary winding 6 and R.sub.a is equal to the resistance value of the terminating resistance 7.
The known compensation current sensors operate predominantly with a terminating resistance that is connected in series with the secondary winding against a reference potential. By this means, for the compensation of a positive current a positive (or, respectively, negative) supply voltage is required, and for the compensation of a negative current a negative (or, respectively, positive) supply voltage is required. As a consequence, a bipolar voltage supply must be provided. If no such voltage supply is available, two bipolar voltages can be obtained from a unipolar voltage source by voltage halving; however, the individual voltage values thereof are thereby also halved. However, due to the halved voltage values the maximal measurable voltage is also reduced according to the above equation.


The present invention is directed to a method of controlling chemical mechanical polishing operations to control the duration of an endpoint polishing process. The method comprises providing a wafer having a layer of copper formed thereabove, performing a first timed polishing operation for a duration (t1) on the layer of copper at a first platen to remove a majority of the layer of copper, performing an endpoint polishing operation on the layer of copper at a second platen to remove substantially all of the layer of copper, determining a duration (t2ept) of the endpoint polishing operation performed on the layer of copper at the second platen, and determining, based upon a comparison between the determined duration (t2ept) of the endpoint polishing operation and a target value for the duration of the endpoint polishing operations, a duration (t1) of the timed polishing operation to be performed on a subsequently processed layer of copper at the first platen. In another embodiment, the invention further comprises modifying, based upon a variance between the determined duration (t2ept) of the endpoint polishing operation and a target value for the duration (t2ept) of the endpoint polishing operation, the duration (t1) of the timed polishing operation to be performed on a subsequently processed layer of copper at the first platen.

1. Field of the Invention
The present invention is generally directed to the field of semiconductor manufacturing, and, more particularly, to a method of controlling the duration of an endpoint polishing process in a multistage polishing process.
2. Description of the Related Art
There is a constant drive within the semiconductor industry to increase the operating speed of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for computers and electronic devices that operate at increasingly greater speeds. This demand for increased speed has resulted in a continual reduction in the size of semiconductor devices, e.g., transistors. That is, many components of a typical field effect transistor (FET), e.g., channel length, junction depths, gate insulation thickness, and the like, are reduced. For example, all other things being equal, the smaller the channel length of the transistor, the faster the transistor will operate. Thus, there is a constant drive to reduce the size, or scale, of the components of a typical transistor to increase the overall speed of the transistor, as well as integrated circuit devices incorporating such transistors.
In modem integrated circuit devices, millions of transistors are formed above a surface of a semiconducting substrate. To perform their intended functions, these transistors, or groups of transistors, are electrically coupled together by many levels of conductive interconnections, i.e., conductive metal lines and plugs. These conductive lines and plugs allow electrical signals to propagate throughout the integrated circuit device.
In general, these conductive interconnections are formed in layers of insulating material, e.g., silicon dioxide, HSQ, or other materials that may have a dielectric constant less than approximately 4. The insulating materials electrically isolate the various conductive interconnections and tend to reduce capacitive coupling between adjacent metal lines when the integrated circuit device is in operation. Moreover, modem integrated circuit devices are very densely packed, i.e., there is very little space between the semiconductor devices, as well as between the conductive metal lines. Accordingly, the amount of insulating material positioned between adjacent metal lines, and other surrounding conductive structures, both above and below the metal lines, is very important.
As the demand for high performance integrated circuit devices continues to increase, circuit designers and manufacturers look for ways to improve device performance. Recently, copper has become the material of choice for conductive interconnections for high performance integrated circuit devices, e.g., microprocessors, due to its lower resistance as compared to, for example, aluminum.
Typically, a layer of insulating material will be formed on or above a semiconducting substrate. Thereafter, a plurality of openings will be formed in the layer of insulating material using known photolithographic and etching techniques. Then, after the formation of a barrier metal layer, e.g., tantalum, a layer of copper will be formed above the insulating layers and in the openings in the insulating layer by performing an electroplating process. Next, the excess copper material positioned outside of the openings in the insulating layer is removed by performing one or more chemical mechanical polishing operations.
Such chemical mechanical polishing operations may involve polishing tools in a sequence of polishing operations. For example, the bulk of the excess copper may be removed during an initial, timed polishing process. The removal rate during the initial timed etch process may be relatively high. Thereafter, an endpoint etch process may be performed to remove the remaining copper material. The removal rate during this endpoint process may be relatively low. Additional polishing operations may be performed on the device after these steps are performed.
Problems may arise when the incoming layer of copper is thicker or thinner than anticipated. For example, if the incoming thickness of the layer of copper is thicker than anticipated, the initial timed polishing process may not remove enough of the incoming layer of copper. As a result, the endpoint process may be performed for too long of a duration. As a result, manufacturing efficiencies are reduced and the overall output of the manufacturing facility may be reduced. Alternatively, if the layer of copper is thinner than anticipated, the initial timed polishing operation may remove too much of the copper layer, to the point that the operations may unnecessarily consume too much of the underlying insulating layer.
The present invention is directed to a method that may solve, or at least reduce, some or all of the aforementioned problems.
The present invention is directed to a method of controlling chemical mechanical polishing operations to control the duration of an endpoint polishing process. The method comprises providing a wafer having a layer of copper formed thereabove, performing a first timed polishing operation for a duration (t1) on the layer of copper at a first platen to remove a majority of the layer of copper, and performing an endpoint polishing operation on the layer of copper at a second platen to remove substantially all of the layer of copper remaining after the timed polishing operation performed at platen 1. The method further comprises determining a duration (t2ept) of the endpoint polishing operation performed on the layer of copper at the second platen, and determining, based upon a comparison between the determined duration (t2ept) of the endpoint polishing operation at platen 2 and a target value for the duration of the endpoint polishing operations, a duration (t1) of the timed polishing operation to be performed on a subsequently processed layer of copper at the first platen. In another embodiment, the invention further comprises modifying, based upon a variance between the determined duration (t2ept) of the endpoint polishing operation and a target value for the duration (t2ept) of the endpoint polishing operation, the duration (t1) of the timed polishing operation to be performed on a subsequently processed layer of copper at the first platen.

Method of controlling the duration of an endpoint polishing process in a multistage polishing process


Apparatuses and methods for securing and positioning an axle relative to a cycle frame are provided. An adjustor block is placed in a cavity of the cycle frame. The block can slide longitudinally within the frame cavity. An axle bolt is inserted into the cavity and seated against a bearing surface of the adjustor block for engagement with the adjustor block. The axle bolt is threadedly engaged with the axle, thereby coupling the axle to the adjustor block. An adjustor bolt is inserted into a bore in the cycle frame and used to move the adjustor block longitudinally within the frame cavity, which in turn moves the axle longitudinally relative to the frame. The frame and axle assembly are both functional and aesthetically pleasing without the use of axle covers.

Motorcycles typically include a frame that, directly or indirectly, is supported by front and rear axles and wheels. An axle dropout refers to that portion of a cycle frame that allows for removal of the axle. In many designs, the rear axle extends through a rear or dropout portion of the frame and is secured in place by an axle nut or axle bolt. The positioning of the axle relative to the frame can be changed by use of an axle adjuster. The axle nut can be loosened and the adjuster used to move the rear axle relative to the frame to change the tension in a drive chain or belt.
In some designs, portions of the rear axle or adjuster are covered. For example, rear axles and corresponding axle nuts can be covered with an axle end cap or cover. Some rear axle covers provide both functional and decorative additions to cycles. They can include brightly polished exteriors and can have ornamental designs or logos. However, it is desirable to have alternatives that do not employ axle covers yet provide both functional and aesthetically pleasing components for securing an axle to a cycle frame.

Apparatus and method for securing an axle to a frame


An orthodontic shape-memory alloy archwire for ligating to orthodontic appliances is heat treated, so that different sections of the archwire each exhibit a predetermined modulus of elasticity, and therefore impart a predetermined range of force when deflected. The distal ends of the archwire are further heat treated, or are treated with a dopant, to exhibit substantially diminished superelastic properties in comparison to the other sections of the archwire. The distal ends can therefore be deformed into shapes when ligated to orthodontic appliances to secure them to the appliances, and thus prevent them from slipping therethrough.

A variable force archwire made from a nickel-titanium (Ni-Ti) alloy wire is shown in Japanese utility model publication SHOO 63-34650 (1988). Different sections of the archwire are treated to develop different moduli of elasticity, thus imparting different forces when deflected. Typically, the sections corresponding to the front teeth, the bicuspids, and the molars are heat treated differently so that each section exhibits a unique modulus of elasticity. As a result, when the archwire is mounted to a patient's teeth, it imparts different forces to different sections of the dental arch.
A typical variable force archwire is heat treated so that its section corresponding to the molars imparts a greater force when deflected than its section corresponding to the bicuspids. The section corresponding to the bicuspids is typically heat treated to impart a greater force when deflected than the section corresponding to the front teeth.
One problem with non-variable force archwires is that the entire length of such an archwire exerts substantially the same force when deflected. Therefore, because it is necessary to impart different forces to different sections of a patient's dental arch, more than one archwire must be employed during the course of treatment. Typically, 7 to 8 different archwires may be used to treat a single patient. With variable force archwires, however, fewer archwires are required.
In FIG. 1, the teeth T of a typical dental arch are illustrated. An orthodontic archwire W is ligated to several orthodontic brackets B mounted to the teeth T. The bending and resultant tension within the archwire W creates forces that are imparted to the brackets B and thus the teeth T. The distal ends WA of the archwire W are secured to the brackets B mounted to the anterior molars, to prevent the archwire from slipping in the mesial direction.
With known stainless steel orthodontic archwires, the distal ends are typically bent into appropriate shapes to prevent them from slipping through the orthodontic brackets B. Typical stainless steel archwires are illustrated in FIGS. 2 and 3. As shown in FIG. 2, the distal end WA of the archwire W is formed into a triangular shape. In FIG. 3, the distal end WA is formed into a hook shape. The bent distal ends are often referred to as "stops".
One problem with shape-memory alloy archwires, such as Ni-Ti archwires, is that it has not been possible to bend their distal ends to form stops. Because of the properties of shape-memory alloy wires, when their distal ends are bent to form stops, the bent shapes are not retained because the archwires tend to return to their original shapes. It has been necessary therefore to attach fastening accessories to their distal ends to prevent them from slipping through the orthodontic appliances. For example, stop tubes are typically mechanically fastened to the distal ends of shape-memory alloy archwires. The procedure of attaching fastening accessories, however, has proven to be relatively complicated and time consuming.
It is an object of the present invention, therefore, to overcome the problems and disadvantages of known shape-memory alloy archwires.


A stop mechanism for a door associated with a jamb utilizing an arresting element. The arresting element is capable of withstanding force asserted on an object normally positioned between the door and the jamb. In addition, the arresting element is sized to provide a gap between the door and the jamb when the door is swung toward a closed position. A tether is also employed in the present invention which is connected to the arresting element, and permits the arresting element to lie in a first position in the vicinity of the closed door and associated jamb and in a second position between the door and the jamb when the door is again motivated toward closing. The tether is supported to the vicinity of the door jamb at a selected level above the ground surface.

The present invention relates to a novel stop mechanism for a door associated with a jamb.
Many items have been developed to prevent doors from opening or closing. The typical door stop includes a weighted item which is normally placed on the floor in the vicinity of the door such that the door cannot travel, normally along a rotational path. For example, U.S. Pat. Des. Nos. 286,015 and 302,939 describe doorstops which are free standing.
Other door stops have been devised that are connected to door and prevent movement of the door by simply serving as an extension of the dimension of the door. For example, U.S. Pat. No. 4,782,553 depicts this type of door stop.
U.S. Pat. No. 3,639,943 shows a door stop which has a hinge pin parallel to the door hinge pin and carries a movable finger which connects with a catch to lock a car door or folded into immediate position between the open and closed position.
A door stop mechanism which is simple to use, versatile, and effective would be a great advance in the building art field.


A media isolated pressure sensor is disclosed that helps improve performance and reduce cost. In one illustrative embodiment, a pressure sensor may include a carrier having one or more holes defined therein. The carrier may be coupled to a diaphragm on one side, and a pressure sensing die on the other, with the pressure sensing die in fluid communication with the hole in the carrier. The carrier, diaphragm and pressure sense die may form a transfer fluid cavity, which is filled with a pressure transfer fluid. An input pressure from a media to be sensed may be provided to the diaphragm, which transmits the pressure to the pressure sensing die via the pressure transfer fluid. The pressure sensing die remains isolated from the media to be sensed.

Pressure sensors are used in a wide variety of applications including, for example, commercial, automotive, aerospace, industrial, and medical applications. Pressure sensors often use a pressure sense element that is configured to detect a pressure of a media to be sensed by converting mechanical stress caused by the incoming pressure of the media into an electrical output signal. In some applications, it may be desirable to isolate the pressure sense element from the media. This is sometimes accomplished by providing a pressure transfer fluid (such as oil) between the pressure sense element and a diaphragm. Typically, pressure from the media is applied to the diaphragm, which is then transferred through the pressure transfer fluid and ultimately to the pressure sense element. While such configurations may help isolate and protect the pressure sense element from the media, they can be expensive to build, and they can have relatively high offset variation with temperature, often caused by relatively high aspect ratios (height to width, traditionally ranging from 1:1 to 1:10) of the cavity holding the pressure transfer fluid, which must be calibrated out to produce accurate results.


A device made of non-contaminating inert material for taking and preserving a fluid sample containing volatile substances for analysis having a tubular body with gas tight valves at opposite end portions which are opened to allow fluid to pass into and out of a chamber and closed to seal off the escape of and preserve a fluid sample therein during transfer to a laboratory for analysis. Opposite end portions of the tubular body are adapted for attachment of a lower one-way inlet check valve unit and an upper outlet extension unit thereto used with a supporting line or rod to lower and raise the device into and out of a body of fluid and thereby take a fluid sample thereof for analysis. Closing of the valves traps fluid and seals off the sample taken into the chamber between the valves and is removed therefrom by piercing a septum located adjacent the chamber and between the valves by suitable means including a hypodermic needle.

1. Field of the Invention
The invention relates to devices for taking a sample from various bodies of fluids such as water from underground wells, tanks, barrels, and reservoirs and sealing the contents thereof against any loss or addition of volatile substances and contaminates during transfer to a laboratory for analysis.
2. Description of the Prior Art
Heretofore samples of a body of fluid/liquid such as water to be analyzed for contamination and volatile substances has been obtained by lowering a vessel such as a bailer into the body of liquid to be tested. When filled, the bailer containing the sample is withdrawn to the surface whereupon a valve at one or both bottom and top ends close to contain the liquid therein. One such sampling device which seals off the upper and lower ends thereof is disclosed in U.S. Pat. No. 2,059,999.
Another known device which seals a liquid sample between a septum cap later screwed onto its upper end and a lower ball check valve is disclosed in U.S. Pat. No. 4,625,574.
Still another device for obtaining and transferring a gas sample for analysis has a septum pierceable by a hypodermic needle sealing off the lower exit end thereof is shown in U.S. Pat. No. 3,886,800. However, unlike the applicant's device, the prior art device allows possible opening of the check valves and thus addition or escape of gases or volatile substances which may be present in the fluid sample during handling and preparation of the device for transfer to another container and to the laboratory for analysis.
The applicant's device differs from the prior art in that no transfer of the fluid sample to another container takes place. The applicant's device has means for taking and positively preserving the fluid sample and preventing the escape of any of the constituents of the sample including gases and volatiles during, taking, handling, and transfer of the fluid sample for analysis.

Device for taking, preserving and transporting a fluid sample for analysis


To prevent, in the case of irradiating a single crystal semiconductor layer with a laser beam, an impurity element from being taken into the single crystal semiconductor layer at the time of laser irradiation. In a manufacturing method of an SOI substrate, a single crystal semiconductor substrate and a base substrate are prepared; an embrittlement region is formed in a region at a predetermined depth from a surface of the single crystal semiconductor substrate by irradiating the single crystal semiconductor substrate with accelerated ions; the single crystal semiconductor substrate and a base substrate are bonded to each other with an insulating layer interposed therebetween; a single crystal semiconductor layer is formed over the base substrate with the insulating layer interposed therebetween by heating the single crystal semiconductor substrate to cause separation using the embrittlement region as a boundary; an oxide film formed on the single crystal semiconductor layer is removed; and at least a surface of the single crystal semiconductor layer is melted by irradiating the surface of the single crystal semiconductor layer with a laser beam after the removal of the oxide film. The number of times the single crystal semiconductor layer is melted by the irradiation with the laser beam is one.

1. Field of the Invention
The present invention relates to a manufacturing method of a substrate provided with a semiconductor layer with an insulating layer interposed therebetween, and particularly a manufacturing method of an SOI (silicon on insulator) substrate. Further, the present invention relates to a manufacturing method of a semiconductor device in which a substrate provided with a semiconductor layer with an insulating layer interposed therebetween is used.
2. Description of the Related Art
In recent years, integrated circuits using an SOI substrate where a thin single crystal semiconductor layer is formed on an insulating surface, instead of a bulk silicon wafer, have been developed. Since parasitic capacitance between a drain of a transistor and a substrate is reduced by using the SOI substrate, the SOI substrate has attracted attention as one improving performance of semiconductor integrated circuits.
One of the manufacturing methods of SOI substrates is a Smart Cut (registered trademark) method (e.g., see Patent Document 1). An outline of the manufacturing method of an SOI substrate by a Smart Cut method is described below. First, hydrogen ions are implanted into a silicon wafer by an ion implantation method to form a microbubble layer at a predetermined depth from the surface. Then, the silicon wafer into which the hydrogen ions are implanted is bonded to another silicon wafer with a silicon oxide film interposed therebetween. Then, by performing heat treatment, part of the silicon wafer into which hydrogen ions have been implanted is separated in a thin film shape along the microbubble layer which serves as a cleavage plane. Accordingly, a single crystal silicon film can be formed over the other bonded silicon wafer. Here, a Smart Cut method may also be referred to as a hydrogen ion implantation separation method.
Further, a method has also been proposed in which a single crystal silicon layer is formed over a base substrate made of glass by such a Smart Cut method (e.g., see Patent Document 2). Since glass substrates can have a larger area and are less expensive than silicon wafers and are transparent, the glass substrates are mainly used in manufacturing liquid crystal display devices and the like. By using such a glass substrate as a base substrate, a large-sized inexpensive SOI substrate can be manufactured.
In addition, a method of irradiating the single crystal silicon layer with a laser beam for improvement in crystal quality of the single crystal silicon layer is disclosed in Patent Document 2.
[Reference]
[Patent Document]
    [Patent Document 1] Japanese Published Patent Application No. H05-211128    [Patent Document 2] Japanese Published Patent Application No. 2005-252244

Manufacturing method of SOI semiconductor device

Semiconductor Energy Laboratory Co., Ltd.


An air-conditioning apparatus includes a plurality of indoor units each located inside a building and at a position that enables the indoor unit to condition air, and a relay unit installed in a space not to be air-conditioned inside the building. The relay unit and each indoor unit are connected to each other via a first heat medium pipe in which a first heat medium such as water or brine flows. The relay unit accommodates therein a first refrigerant circuit including a compressor, a plurality of first intermediate heat exchangers that exchange heat between the first heat medium and refrigerant that performs a phase shift or turns to a supercritical state during operation, a plurality of expansion devices, and a second intermediate heat exchanger that exchanges heat between the refrigerant and a second heat medium, which are connected via a refrigerant pipe.

Some air-conditioning apparatuses such as multi-air-conditioning apparatuses for building are configured to circulate refrigerant, for example between an outdoor unit installed outdoors and indoor units located inside the rooms, to perform a cooling operation or heating operation. More specifically, the refrigerant transfers heat to air so as to heat the air or removes heat from the air so as to cool the air, and such heated or cooled air is utilized to heat or cool the space to be air-conditioned. In such a type of air-conditioning apparatus, for example hydrofluorocarbon (HFC)-based refrigerant is often employed. In addition, air-conditioning apparatuses that employ a natural refrigerant such as carbon dioxide (CO2) have also been proposed.
Further, air-conditioning apparatuses differently configured, typically represented by a chiller system, have been developed. In this type of air-conditioning apparatus, cooling energy or heating energy is generated in the outdoor unit installed outdoors, and a heat medium such as water or antifreeze solution is heated or cooled with a heat exchanger provided in the outdoor unit. Then the heat medium is transported to the indoor unit located in the region to be air-conditioned, such as a fan coil unit or a panel heater, so as to cool or heat the region to be air-conditioned (see, for example, Patent Literature 1).
In addition, an outdoor-side heat exchanger, called exhaust heat collection chiller, is known in which the outdoor unit and the indoor units are connected via four water pipes, and cooled or heated water is supplied at the same time so as to allow each of the indoor units to select cooling or heating operation as desired (see, for example, Patent Literature 2).
Further, an air-conditioning apparatus is known in which a heat exchanger for heat exchange between the refrigerant and the heat medium is located in the vicinity of each indoor unit, and the heat medium is supplied from the heat exchanger to the indoor unit (see, for example, Patent Literature 3).
Further, an air-conditioning apparatus is known in which the outdoor unit and branch units each including a heat exchanger are connected via two pipes, so as to supply the heat medium to the indoor unit (see, for example, Patent Literature 4).
Still further, an air-conditioning apparatus is known in which the outdoor unit and a relay unit are connected via two refrigerant pipes, and the relay unit and the indoor units are connected via two pipes through which a heat medium such as water circulates, so as to transfer heat from the refrigerant to the heat medium in the relay unit, thereby allowing the cooling and heating operation to be performed at the same time (see, for example, Patent Literature 5).


Feed oil is subject to atmospheric distillation, to thereby be separated into light oil or light distillate and atmospheric residue oil. The light distillate is catalytically contacted with pressurized hydrogen in the presence of a catalyst, resulting in a first hydrotreating step being executed. In this instance, various fractions of the light distillate produced in the atmospheric distillation are subject to hydrotreating in a lump. The atmospheric residue oil is then separated into a light matter and a heavy matter. The light matter is subject to second hydrotreating in the presence of a catalyst to produce refined oil (light matter), which is mixed with refined oil produced in the first hydrotreating to prepare a mixture. The mixture is used as gas turbine fuel oil.

In general, oil thermal power generation is adapted to generate steam at a high pressure in a boiler using crude oil and/or heavy oil as a fuel for the boiler, to thereby rotate a steam turbine by means of the thus-generated steam, leading to power generation. However, such a system is deteriorated in power generation efficiency. Currently, a high-efficiency large-sized oil-fired boiler is developed, however, it merely exhibits generation efficiency as low as about 40%. Thus, it causes a large part of energy to be outwardly discharged in the form of greenhouse gas without being recovered. In addition, it causes a certain amount of SOx to be present in exhaust gas or flue gas discharged therefrom. Although the exhaust gas is subject to flue gas desulfurization, SOx is partially discharged to an ambient atmosphere, leading to environmental pollution.
Further, a gas turbine combined cycle power generation system is executed which is adapted to drive a gas turbine for power generation using natural gas as a heat source therefor and recover waste heat from high-temperature flue gas or exhaust gas discharged from the gas turbine for production of steam, to thereby drive a steam turbine, leading to power generation. The system comes to notice in the art because it is increased in power generation efficiency, reduced in quantity of CO2 generated per unit power generation and highly reduced in content of SOx and NOx in flue gas. When it uses natural gas as feed gas, it is required to transport it from a gas field to a power generation plant through a pipeline or store LNG and gasify it, followed by combustion of it in the gas turbine. Unfortunately, this leads to an increase in cost of equipment.
In view of the foregoing, a method for producing fuel oil for a gas turbine is proposed as disclosed in Japanese Patent Application Laid-Open Publications Nos. 207179/1994 and 209600/1994. Techniques disclosed in the former Japanese publication are constructed so as to subject low-sulfur crude oil having a salt content adjusted to be 0.5 ppm or less to a separation treatment by atmospheric distillation or vacuum distillation to produce gas turbine fuel oil constituted of a low boiling fraction of 0.05% by weight in sulfur content. Techniques disclosed in the latter Japanese Publication are adapted to heat low-sulfur crude oil using waste heat discharged from a gas turbine and then act hydrogen on the low-sulfur crude oil, to thereby reduce a sulfur and heavy metal content in the crude oil, followed by recovery of crude oil thus refined, which is then used as fuel oil for the gas turbine.
Now, an environmental problem comes to notice in the art. Thus, it is highly required to minimize a content of a sulfur compound in flue gas. This would be solved by employment of a flue gas desulfurization unit. Unfortunately, in power generation using gas turbine fuel oil, arrangement of the flue gas desulfurization unit causes a deterioration in power generation efficiency due to a pressure loss, so that it is required to minimize a sulfur content of gas turbine fuel oil. Thus, the techniques of the former Japanese publication cause the amount of firing of oil to be considerably restricted in the atmospheric distillation or vacuum distillation, to thereby fail to increase the amount of light oil or light distillate to be fed to the gas turbine or the amount of gas turbine fuel oil. This causes yields of gas turbine fuel oil based on crude oil to be as low as a level of 40%, even if Middle East crude oil which has a low sulfur content is used. An increase in firing of oil for the purpose of increasing the yields causes an increase in production of sulfur.
Also, when it is applied to crude oil which is readily available and increased in sulfur content, recovery of light oil or light residue in the same amount causes a sulfur content of the light oil to exceed a specified level, so that it is unsuitable for use as fuel oil for a gas turbine. Thus, it is forced to decrease recovery of the light oil, resulting in application to the crude oil being technically and economically disadvantageous.
The latter Japanese publication discloses techniques of producing hydrogen using methanol as a starting material and subjecting crude oil to hydrotreating with the hydrogen thus produced. However, the techniques are constructed so as to treat crude oil at a low sulfur content, so that application of the techniques to crude oil at a high sulfur content is considerably restricted. Further, the hydrotreating is carried out on crude oil rather than light oil or light distillate obtained by distillation of crude oil, so that it is required to accommodate process conditions to heavy oil or residue contained in crude oil. This requires to increase a reaction temperature, a reaction pressure and reaction time or a period of time during which heavy oil is kept contacted with a catalyst in the reaction. Unfortunately, this causes excessive cracking of light oil in the crude oil, resulting in LPG or the like being contained in a large amount in fuel oil for a gas turbine, so that storage of the fuel oil causes a part thereof to be gasified. This requires to increase pressure resistance of a tank to a significantly high level. Also, the reaction temperature and reaction pressure are caused to be increased, so that a reaction vessel for the hydrotreating is complicated in structure and increased in manufacturing cost. Further, an increase in reaction time requires large-sizing of a catalyst carrier, leading to large-sizing of the reaction vessel and an increase in consumption of a catalyst.

Gas turbine fuel oil and production method thereof and power generation method


A suturing gun which includes a conventional stitch applying device and comprises pliers for clamping the wound margins arranged close to the stitch outlet, further includes an external control element for actuating the pliers arranged at an easily accessible location for the surgeon when grasping the gun, and a driving system for transmitting the movement of the control element to the pliers. The suturing gun further comprises housing means for containing and retaining one or more gauze tampons, a first dispenser for containing and dispensing a disinfectant liquid or the like and a second dispenser for containing and dispensing a suture adhesive.

1. Field of the Invention
The present invention relates generally to suturing devices and, more particularly, to an improved suturing gun which can be operated with one hand so as to facilitate the suturing operation.
2. Description of the Prior Art
In the surgery field, mechanical suturing devices for suturing the skin are already known, and are generally produced in the shape of a gun. In use, a suturing gun of this kind is grasped by the surgeon with one hand, while he operates a forceps with the other hand in order to clamp the margins of the wounded skin together and maintain them in this clamped position so that the stitches delivered by the suturing gun can grip both the wound margins, such that the wound is properly closed. This procedure is very toilsome for the surgeon and often, to facilitate this operation, the mechanical suturing device is grasped by the right hand of the surgeon and the clamping of the skin margins is carried out by an assistant who operates a pair of toothed forceps to hold the wound margins clamped until the stitches have been applied. The latter solution facilitates the surgeon's task but requires the presence of two operators and therefore increases overall cost of the operation.
It is also known that during the suture operation the surgeon needs to have gauze tampons at his immediate disposal to plug the wound, as well as disinfectant liquids and suture adhesives in order to maintain the wound disinfected during the suture operation and sutured after the suture operation. The application of these products requires again the presence of a second operator during the suturing operation made by the surgeon, which operator must give the surgeon gauze tampons, disinfecting liquid and/or adhesive on request.

Improvements in automatic mechanical suturing guns