A polycide gate structure and a method of forming the polycide gate. A substrate having a gate dielectric layer, a polysilicon layer, a silicide layer and an insulation layer thereon is provided. The polysilicon layer is above the gate dielectric layer, the silicide layer is above the polysilicon layer, and the insulation layer is above the silicide layer. A patterned photoresist layer is formed over the insulation layer. Using the photoresist layer as a mask, an anisotropic etching operation is carried out to remove the exposed insulation layer. Again using the photoresist layer as a mask, a first type of plasma is used to carry out a first anisotropic etching operation to remove the exposed silicide layer. A metallic oxide layer is formed on the sidewalls of the silicide layer by the oxidation of a portion of the retained silicide layer. Using the photoresist layer as a mask, a second type of plasma is used to carry out a second anisotropic etching operation to remove the exposed polysilicon layer. The metallic oxide layer is resistant to attack by the second type of plasma.

1. Field of the Invention
The present invention relates to a semiconductor structure and method of manufacture. More particularly, the present invention relates to a polycide gate structure and method of manufacture.
2. Description of Related Art
As dimensions of semiconductor devices continue to shrink, electrical resistance of interconnecting lines will increase. To reduce electrical resistance, a silicide layer is normally deposited over the polysilicon gate in most MOS manufacturing processes to form a polycide gate structure. FIG. 1 is a schematic cross-sectional view showing a conventional polycide gate structure. To form a conventional polycide gate, a gate dielectric layer 110, a conformal polysilicon layer 120, a silicide layer 130, a silicon nitride layer 140 and a patterned photoresist layer 150 are sequentially formed over a substrate 100. Using the patterned photoresist layer 150 as a mask, an anisotropic etching operation is carried out to etch the silicon nitride 140, the silicide layer 130 and the polysilicon layer 120 sequentially to form the polycide gate. The silicon nitride layer 140 serves as a cap layer in a subsequent self-aligned contact process. In the etching step, HBr/Cl2 plasma 170 is often used for etching the polysilicon layer 120. In general, chlorine plasma (Cl2) is rarely used alone because serious undercutting of the polysilicon layer 120 may occur resulting in poor quality. On the other hand, if hydrogen bromide (HBr) plasma is used alone, line width of gates in different areas of a wafer may be affected leading to a variation in the electrical properties of devices. Etching with HBr/Cl2 plasma is able to prevent both undercutting and line width problems.
However, when the polysilicon layer 120 is etched using HBr/Cl2 plasma 170, the sidewalls of the silicide layer 130 above the polysilicon layer 120 may be attacked by highly reactive Cl2 plasma. Ultimately, recesses 135 may form due to the undercutting of the silicide layer 130.
FIG. 2 is a schematic cross-sectional view showing an improved version of a conventional gate polycide structure. The newer version is able to prevent the undercutting of the silicide layer when the polysilicon layer is etched. To form the gate structure as shown in FIG. 2, a gate dielectric layer 210, a conformal polysilicon layer 220, a silicide layer 230, a silicon nitride layer 240 and a patterned photoresist layer 250 are sequentially formed over a substrate 200. The photoresist layer 250 has a width L. Using the photoresist layer 250 as a mask, an anisotropic etching operation is carried out to etch the silicon nitride layer 240 and the silicide layer 230 in sequence. The exposed polysilicon layer 220 is etched using HBr/Cl2 plasma with CF4 or C2F6 molecules therein to form a polycide gate 280. The presence of CF4 or C2F6 molecules in the plasma will result in a carbon chain polymerization. Hence, a protective polymer layer 260 is formed over the sidewalls of the silicide layer 230, the silicon nitride layer 240 and the patterned photoresist layer 250. Hence, corrosion of the silicide layer 230 is prevented. However, thickness of the protective polymer layer 260 in various locations within the wafer is difficult to control. Consequently, fabricating a polysilicon layer 220 of width L just underneath the silicide layer 230 is difficult to do with precision, leading to a deterioration of device properties. In addition, the additives CF4 and C2F6 are not quite suitable for etching polysilicon layer 220 when a silicon nitride layer is used as a hard mask. This is because CF4 and C2F6 plasma has a high etching rate for silicon nitride. Consequently, too much silicon nitride may be removed from the silicon nitride layer 240. Ultimately, subsequent process for forming a self-aligned contact may be affected.
Accordingly, one object of the present invention is to provide a method of forming a polycide gate. A substrate having a gate dielectric layer, a polysilicon layer, a silicide layer and an insulation layer thereon is provided. The polysilicon layer is formed above the gate dielectric layer, the silicide layer is formed above the polysilicon layer, and the insulation layer is formed above the silicide layer. A patterned photoresist layer is formed over the insulation layer. Using the photoresist layer as a mask, an anisotropic etching operation is carried out to remove the exposed insulation layer. Again using the photoresist layer as a mask, a first type of plasma is used to carry out a first anisotropic etching operation to remove the exposed silicide layer. A metallic oxide layer is formed on the sidewalls of the silicide layer by the oxidation of a portion of the retained silicide layer. Using the photoresist layer as a mask, a second type of plasma is used to carry out a second anisotropic etching operation to remove the exposed polysilicon layer. The metallic oxide layer is resistant to attack by the second type of plasma.
In addition, the method of forming a polycide gate in this invention further includes removing the photoresist layer after the first anisotropic etching step. Hence, the patterned insulation layer becomes the hard mask layer in the second anisotropic etching step.
This invention utilizes the formation of a metallic oxide layer on the sidewalls of the silicide layer after the first anisotropic etching step. Hence, the silicide layer is protected from reactive components inside the second type of plasma by the metallic oxide layer when the polysilicon layer is etched in the second anisotropic etching step. In other words, undercutting of the silicide layer is prevented. Furthermore, since no additives such as CF4 and C2F6 molecules are added to the reactive plasma in the polysilicon etching operation, thickness variation in protective polymer layer across the wafer no longer presents a problem. Moreover, even if an insulation layer fabricated from silicon nitride material is used as an etching hard mask, loss of insulation material no longer presents a problem for forming self-aligned contacts in a subsequent operation.
This invention also provides a polycide gate structure. The polycide gate structure is formed by the aforementioned method. The structure is formed on a substrate having a gate dielectric layer thereon. The polycide gate structure includes a patterned polysilicon layer, a silicide layer, a metallic oxide layer and an insulation layer. The polysilicon layer is above the gate dielectric layer. The silicide layer is above the polysilicon layer. The metallic oxide layer is on the sidewalls of the silicide layer. The metallic element within the metallic layer is identical to the metallic element within the silicide layer. The insulation layer is above the silicide layer.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.

Polycide gate structure and method of manufacture


Semiconductor devices are provided. A semiconductor device includes a stack of alternating insulation layers and gate electrodes. The semiconductor device includes a channel material in a channel recess in the stack. The semiconductor device includes a charge storage structure on the channel material, in the channel recess. Moreover, the semiconductor device includes a gate insulation layer on the channel material. The gate insulation layer undercuts a portion of the channel material. Related methods of forming semiconductor devices are also provided.

The present disclosure relates to semiconductor devices. When a non-volatile semiconductor memory device is manufactured, a channel hole may be formed through insulation layers and sacrificial layers that are alternately and repeatedly stacked on a substrate. A semiconductor pattern may be formed in a lower portion of the channel hole. An Oxide-Nitride-Oxide (ONO) layer and a channel may be formed in an upper portion of the semiconductor pattern. An opening may be formed through the insulation layers and the sacrificial layers, and the sacrificial layers exposed by the opening may be removed to form gaps exposing sidewalls of the ONO layer and the semiconductor pattern. Gate electrodes may be formed to fill the gaps.
Controlling breakdown voltages of word lines and String Select/Selection Lines (SSLs), which may be formed at relatively high (e.g., upper) levels among the gate electrodes, may be possible because the ONO layer may be formed between the word lines and the channel, and between the SSLs and the channel. Controlling breakdown voltages of Ground Select/Selection Lines (GSLs), however, which may be formed at relatively low (e.g., lower) levels among the gate electrodes, may be more difficult because the GSLs may directly contact the semiconductor pattern.

Semiconductor devices including gate insulation layers on channel materials


A directional diffusion film with diffusion properties that vary depending on the incidence angle is characterized in that a diffusion axis direction is in the range of 20° to 50° with respect to a normal direction of the film, and a diffusion half-value angle is at least 20° and lower than 90°. The diffusion axis direction is a light irradiation direction in which the strongest diffusion light is obtained when the film is irradiated with light. The diffusion half-value angle is a diffusion angle at which intensity of outgoing diffusion light at a plane A is 50% of the peak intensity, with the plane A containing the normal direction and the diffusion axis direction of the directional diffusion film, when collimated light is incident at an incidence angle of 30° from the normal direction of the directional diffusion film in the plane A. A polarizing plate containing the directional diffusion film. An LCD device containing the directional diffusion film.

1. Field of the Invention
The present invention relates generally to directional diffusion films, polarizing plates, liquid crystal displays, and methods of manufacturing directional diffusion films.
2. Description of the Related Art
Recently, liquid crystal displays (LCDs) are used widely in, for example, PCs, automated teller machines (ATMs), and car navigation system equipment. Among LCDs, in a transmissive LCD with a twisted nematic (TN) mode employed therein, for example, viewing angle dependency is high, picture quality changes considerably when it is viewed from an oblique direction at a certain angle or more, and an image to be displayed in black under normal conditions appears whitish, and thus the contrast ratio may decrease or tone reversal may cause difficulty in viewing normal display. Therefore, a method has been proposed in which a light diffusion film is disposed on a front surface of a device for the purpose of securing the viewing angle of a LCD (for example, see JP 10(1998)-10513 A). According to this proposal, the tone reversal is suppressed and the viewing angle increases but there is a problem in that the contrast in the front direction decreases. Therefore, a directional light scattering film has been proposed that cancels the decrease in image quality while balancing a tone reversal prevention effect with contrast maintenance (for instance, see JP2006-133463 A). However, when such a light scattering film is disposed, the tone reversal was improved to some extent but with respect to the downward direction of the liquid crystal panel, it covers only a range of up to around 45°, and the contrast in the front direction of the liquid crystal panel also is improved but is still reduced by 20 to 30%. Accordingly, at present, it cannot be always said that the contrast is sufficient.
As described above, in the methods according to conventional light scattering techniques, the directional scattering properties (properties that the scattering properties vary when the incidence angle is changed) can be obtained only in a specific direction. Accordingly, light that is incident from a specific direction is scattered substantially uniformly when the effect of improving viewing angle dependency is obtained in the specific direction. Therefore a phenomenon occurs that display quality with respect to the other directions deteriorates. That is, the tone reversal suppression in the downward direction of the liquid crystal panel and the maintenance of the front contrast are in a trade-off relationship.

Directional diffusion film, polarizing plate, liquid crystal display, and method of manufacturing directional diffusion film


A soil remedying process for the soil contaminated with a volatile pollutant, which comprises the steps of forming in a probe a remediation site containing a microorganism which can degrade the volatile pollutant, introducing the volatile pollutant into the remediation site in the probe, and degrading the volatile pollutant by the microorganism.

1. Field of the Invention
The present invention relates to a process for remedying a soil contaminated with a pollutant and an apparatus used therefor.
2. Related Background Art
A large amount of chemical compounds or chemical products have been produced with the recent rapid progress in technology and science. Many of these are slowly accumulated in the environment and contaminate the environment. In particular, land where humans live is most easily affected by artificial contamination, and since the environmental water is circulating among the land, hydrosphere, and atmosphere, the environmental pollution of the land is a serious problem which might be expanded to the global level. Well-known examples of soil (land) contaminants include organochloric compounds such as trichloroethylene (TCE), tetrachloroethylene (PCE) and dioxin, aromatic compounds such as toluene, xylene and benzene, and fuel such as gasoline. Organochloric compounds such as trichloroethylene and tetrachloroethylene were once extensively used for washing precision parts as well as for dry cleaning, and contamination of soil and underground water on a large scale due to the leakage of the organochloric compounds are now being revealed. Since such organochloric chemicals are teratogenic and carcinogenic and adversely affect the biosphere, purification of the polluted soil or ground water is now an issue to be solved immediately in addition to the isolation of the pollution source.
Methods for remedying soil polluted with these pollutants include, for example, heat treatment of the dug-up soil, vacuum extraction of the contaminant from the polluted soil and microbial degradation of the pollutant in soil. Although the heat treatment can completely purify the soil, the soil must be dug up since soil under structures cannot otherwise be purified. Moreover, this method is unsuitable for large-scale treatment because of the immense costs of digging and heating. In addition, the organochlorine compounds heated and evaporated from the soil which cause air pollution must be recovered by adsorption to activated carbon and the like, and then the used activated carbon requires safe disposal.
On the other hand, vacuum extraction and bioremediation do not require digging up soil, therefore they are inexpensive and simple processes and can be applied to the soil under the buildings while the ground surface is occupied by the buildings. The vacuum extraction process, however, requires the same treatment of the recovered organochlorine compounds as with the heat treatment method. In Japanese Patent Application Laid-Open No. 7-185252, compact ground equipment for vacuum extraction was proposed, utilizing a fluidized bed for regeneration of activated carbon to which the abstracted gas has been adsorbed. Ground equipment is still required for the treatment.
For the bioremediation, there are two methods, one utilizes the pollutant degrading microorganisms originally living in the soil, so-called native microorganisms, and the other utilizes pollutant degrading microorganisms not originally living in the soil. By the former method, remediation is carried out by introducing into the soil activating agents such as nutrients, inducers, oxygen and growth stimulating agents to improve the degradation activity of the native microorganisms.
The examples of strains capable of degrading TCE are given as follows: Welchia alkenophila sero 5 (U.S. Pat. No. 4,877,736, ATCC 53570), Welchia alkenophila sero 33 (U.S. Pat. No. 4,877,736, ATCC 53571), Methylocystis sp. strain M (Agric. Biol. Chem., 53, 2903 (1989), Biosci. Biotech. Biochem., 56, 486 (1992), ibid. 56, 736 (1992)), Methylosinus trichosporium OB3b (Am. Chem. Soc. Natl. Meet. Dev. Environ. Microbiol., 29, 365 (1989), Appl. Environ. Microbiol., 55, 3155 (1989), Appl. Biochem. Biotechnol., 28, 877 (1991), Japanese Patent Application Laid-Open No. (JPUPA) 02-92274, JPUPA 03-292970), Methylomonas sp. MM2 (Appl. Environ. Microbiol., 57, 236 (1991)), Alcaligenes denitrificans ssp. xylosoxidans JE75 (Arch. microbiol., 154, 410 (1990)), Alcaliqenes eutrophus JMP134 (Appl. Environ. Microbiol., 56, 1179 (1990)), Mycobacterium vaccae JOB5 (J. Gen. Microbiol., 82, 163 (1974), Appl. Environ. Microbiol., 54, 2960 (1989), ATCC 29678), Pseudomonas putida BH (Journal of Japan Sewage Work Assosiation, 24, 27 (1987)), Pseudomonas sp. strain G4 (Appl. Environ. Microbiol., 52, 383 (1986), ibid. 53, 949 (1987), ibid. 54, 951 (1988), ibid. 56, 1279 (1990), ibid. 57, 1935 (1991), U.S. Pat. No. 4,925,802, ATCC 53617, this strain was originally classified as Pseudomonas cepacia then classified into Pseudomonas sp.), Pseudomonas mendocina KR-1 (Bio/Technol., 7, 282 (1989)), Pseudomonas putida F1 (Appl. Environ. Microbiol., 54, 1703 (1988), ibid. 54, 2578 (1988)), Pseudomonas fluorescens PFL12 (Appl. Environ. Microbiol., 54, 2578 (1988)), Pseudomonas putida KWI-9 (JPUPA 06-70753), Pseudomonas cepacia KKO1 (JPUPA 06-227769), Pseudomonas sp. (JPUPA 02-273599), Nitrosomonas europaea (Appl. Environ. Microbiol., 56, 1169 (1990)), Lactobacillus vaginalis sp. nov (Int. J. Syst. Bacteriol., 39, 368 (1989), ATCC 49540) and so on. All these strains, however, require a chemical substance such as aromatic compounds and methane as an inducer in order to express their TCE degrading activity.
According to the latter method, remediation is carried out by introducing foreign microorganisms into the soil together with microbial activator for enhancing degradation activity. It is economically desired that microorganisms or chemical substances in an amount as small as possible are introduced and spread into the region to be remedied to carry out the degradation of the pollutants for remediation of the soil. In this sense, the microbial treatment has a drawback since it requires the introduction of a huge amount of a treating solution to remedy a wide region, filling the pore space of the soil to be treated.
With both methods, it is difficult to confine the injected microorganisms or activating agents within a certain region and also difficult to recover the degrading bacteria once proliferated in the soil or the activating agents remaining in the soil after the treatment, causing problems of secondary contamination of the soil.
As mentioned above, the vacuum extraction process and bioremediation process have advantages over the heat treatment method, yet they still have some problems to be solved for more efficient treatment.
In Japanese Patent Application Laid-Open No. 6-254537 and No. 7-112176, it is proposed to combine the vacuum extraction process and the bioremediation process so that air and ground water in the soil contaminated with organochlorine compounds are exposed to vacuum and introduced to a bioreactor on the ground in which the pollutant is degraded. This method aims to solve the drawback of the vacuum extraction process, that is, the reprocessing of the recovered organochlorine compounds, by carrying out biodegradation of the organochlorine compounds, and to solve the drawback of the microbial process such as the injection of the treating solution and the secondary contamination by installing a microbial degradation reactor.
The above-mentioned process in which the vacuum extraction process and the microbial process are combined, still requires ground equipment including a biodegradation reactor, and in this sense, it has the same problem as that of the vacuum extraction process. Since the degradation activity of the microorganism depends on the temperature, an apparatus or equipment to keep the bioreactor at a constant temperature or to protect it from the ambient temperature is further required to assure certain decomposition efficiency. Thus, there is a problem that the scale of the ground equipment of this method becomes larger than that of the vacuum extraction alone.
In other words, large-scale equipment may increase the remediation cost, and huge ground equipment may cancel out the advantage of the vacuum extraction process and the bioremediation process over the heat treatment method, that is, the remediation can be carried out maintaining the state of the soil and the ground surface.

Process for soil remediation and apparatus used therefor

Canon Kabushiki Kaisha & Raito Kogyo Co., Ltd.


Two embodiments of a lantern stand are described for supporting a lantern therefrom. In both embodiments, an extension tube is selectively positioned in either a stowed position or an operative position. In the first embodiment, the extension tube thereof has a spike portion extending downwardly therefrom for insertion into the ground. In the second embodiment, an auger portion extends downwardly therefrom for insertion into the ground. In the second embodiment, a pair of spaced-apart rotatable handles are provided to assist the rotational insertion of the auger portion into the ground.

1. Field of the Invention
This invention relates to a stand for supporting a lantern above the ground at a camping site, fishing site or other location wherein it is desired to illuminate the area in a convenient and safe manner. Further, this invention relates to a lantern stand which includes an extension pole or tube which may be used to elevate a lantern some distance above the ground and which provides a unique means for storing the extension pole or tube during times of storage, travel or non-use.
2. Description of the Related Art
Many types of lantern stands have been previously provided. Further, many types of lantern stands have been previously provided which include extension poles or tubes. However, to the best of Applicant's knowledge, no one has provided a convenient means for storing the extension pole or tube during times of non-use. Additionally, to the best of Applicant's knowledge, the prior art does not disclose a convenient means for driving the lower end of the lantern stand into hard ground.


A self tapping bolt which fastens a mounting member and a receiving member while the bolt cuts internal threads on an inner surface of a tap drill hole prepared in the receiving member. The bolt includes at least one groove formed near an end of a threaded portion of the bolt and a blade for cutting the internal threads. The bolt includes the feature of the blade being formed only on a rear end surface of the groove relative to a rotational direction of the bolt which is screwed into the tap drill hole.

A self tapping bolt, by which a mounting member is fastened to a receiving member while internal threads are being cut in a tapping hole provided in the receiving member so that an independent step of cutting of internal threads can be obviated, is often used for fastening of automobile parts in order to save costs.
FIG. 6 is a sectional view showing fastening of a mounting member and a receiving member with a self tapping bolt. A self tapping bolt 200 reaches a mouth of a tap drill hole 202a provided in a receiving member 202 via a through hole 201a provided in a mounting member 201. If rotational torque is then applied to a head portion 200a, a cutting portion 200d cuts an inner circumferential surface of the tap drill hole 202a to form internal threads thereon and the self tapping bolt 200 is screwed into the tap drill hole 202a simultaneously. When a bearing surface of the self tapping bolt 200 comes into contact with the mounting member 201, joint force begins to act thereon, and then the mounting and receiving members 201, 202 are fastened by the self tapping bolt 200.
Self tapping bolts are generally categorized into two types in terms of method for forming of threads, a cutting type and a rolling type. The former employs cutting and the latter rolling for forming internal threads, respectively.
A self tapping bolt of rolling type, which employs a thread rolling die to exert plastic deformation on the surface of a tap drill hole in order to form internal threads, leaves residual stress therein. This residual stress may cause a problem when a mounting member of low creep strength (e.g. magnesium alloy) is fastened by the self tapping bolt. Creep caused by the residual stress stored during forming of the internal threads and compressive force acting on the mounting member will gradually degrade the joint force of bolt.
Since the material like this for the mounting member generally has a higher coefficient of thermal expansion than that of the bolt, reduction in joint force due to creep poses a problem for elements of engine which are exposed cyclically to high and room temperature conditions. The phenomenon will develop in the following steps. Under high temperature conditions the mounting member experiences thermal expansion which is restricted by the bearing surface of bolt. The bearing surface thus exerts compressive force on the mounting member, thereby developing creep therein. When the temperature of bolt and mounting member then returns to room temperature, the joint force applied to the mounting member by the bearing surface will get smaller than that before exposure to the high temperature environment as the mounting member experiences contraction leaving the creep.
On the other hand, as internal threads are formed by cutting in a tap drill hole provided in a receiving member, a self tapping bolt of cutting type leaves less residual stress in the formed threads. The creep generated in the internal threads can in this way be reduced under the high temperature conditions, and thereby a reduction in joint force (bolt loosening), which occurs when the temperature returns to room temperature, can be restrained better compared with a self tapping bolt of rolling type.
A self tapping bolt according to the prior art has posed a problem that internal threads are unavoidably cut again when a fastened bolt needs to be unscrewed. A typical self tapping bolt of cutting type according to the prior art is shown in FIG. 7.
A self tapping bolt 100 shown in FIGS. 7A and 7B has a cutout 101, the cross section of which occupies a quarter of a circular cross section of threaded portion. When the self tapping bolt 100 is screwed into a tap drill hole in a rotational direction shown by the arrows in the figures, an end surface 101a of cutout 101 cuts a surface of tap drill hole provided in a receiving member, forming internal threads. If the occasion arises that the self tapping bolt 100 needs to be unscrewed, the other end surface 101b unnecessarily cuts the internal threads having already been formed.
A self tapping bolt 110 shown in FIGS. 7C and 7D has three cutouts 111, which are spaced at circumferentially equal intervals. When the self tapping bolt 110 is unscrewed, an end surface 111b of each of cutouts 111 also cuts internal threads having already been formed, like the self tapping bolt 100.
In this way, self tapping bolts such as 100 and 110 have a problem that they can not withstand repeated handling, since the internal threads get thinner each time unscrewing of bolt is conducted, resulting in degradation of dimensional accuracy of threads and a gradual reduction in joint force.


Systems and methods are disclosed for performing cache and I/O management in a multi-layer storage virtualization environment. Block virtualization may be implemented at various layers, each with one or more storage entities. One storage entity may coordinate and leverage the cache and the caching mechanism available with another storage entity. The storage entities may be at the same layer (horizontal cache coordination) or at different layers (vertical cache coordination). Cache coordination may include application-assisted read-ahead.

1. Field of the Invention
This invention relates to data storage and, more particularly, to storage techniques in data storage environments having multiple virtualized layers.
2. Description of the Related Art
Many business organizations and governmental entities rely upon applications that access large amounts of data, often exceeding a petabyte or more of data, for mission-critical applications. Often such data is stored on many different storage devices, which may be centrally located or distributed throughout an enterprise. Such storage devices may be heterogeneous in nature, including many different types of devices from many different manufacturers.
Configuring individual applications that consume data, or application server systems that host such applications, to recognize and directly interact with each different storage device that may possibly be encountered in a heterogeneous storage environment is increasingly difficult as the environment scales in size and complexity. Therefore, in some storage environments, specialized storage management software and hardware may be used to provide a more uniform storage model to storage consumers. Such software and hardware may also be configured to add to the storage model storage features not present in individual storage devices. For example, features to increase fault tolerance, such as data mirroring, snapshot/fixed image creation, or data parity, as well as features to increase data access performance, such as disk striping, may be implemented in the storage model via hardware or software.
Such features may be supplied in a storage model that includes block virtualization. Generally speaking, a block device may comprise a hardware or software entity that provides a collection of linearly addressed data blocks that can be read or written. In block virtualization, a number of virtualized block devices may be created out of one or more physical or logical block devices. Software and/or hardware may be used to rearrange blocks from one or more block devices (e.g., disks) and add various kinds of functions. The resulting rearranged collection of blocks may then be presented to a block device consumer, such as an application or a file system, as one or more aggregated devices with the appearance of one or more basic disk drives. That is, the more complex structure resulting from rearranging blocks and adding functionality may be presented as if it were one or more simple arrays of blocks, or logical block devices.
Volume managers supplied with operating systems may provide block virtualization in a homogenous, proprietary, or otherwise restricted storage environment. Therefore, such volume managers may not satisfy virtualization requirements in a heterogeneous storage environment. Block virtualization functionality may also be supplied by hardware vendors for their storage devices or by network vendors for their switches. Such virtualization functions are usually limited in their scope to a single layer and even a single device in the collection of physical devices. In a heterogeneous storage environment, however, there is no guarantee that virtualization products from a variety of vendors will function in a coordinated or cooperative manner.

Coordination of caching and I/O management in a multi-layer virtualized storage environment


An arrow rest assembly is connected to an archery bow so that an arrow rest is: (i) positioned to support the shaft of an arrow nocked and ready for drawing or drawn and ready for shooting, (ii) positioned to support the shaft of the arrow during an early portion of shooting of the arrow by the bow, and (iii) to allow substantially unimpeded passage of the fletching of the arrow during only the latter portion of shooting of the arrow by the bow. The arrow rest assembly exerts only substantially negligible force on any cable of the bow when the bow is drawn.

The field of the present invention relates to archery bows. In particular, an arrow rest assembly for an archery bow is disclosed herein.
An arrow rest is a structural member attached to an archery bow, typically on the bow's riser or handle, that is arranged to support the shaft of the arrow when the bow is drawn or shot. Such support of the shaft can typically enable the archer to shoot more accurately.
Early examples of arrow rests typically comprised rigid, fixed structures. However, such structures interfere with the fletching of the arrow as the fletching passes the arrow rest during shooting of the arrow with the bow, reducing arrow velocity and degrading the accuracy of the bow. This interference could be reduced somewhat, but not eliminated, by a variety of adaptations. In one example, the fixed arrow rest is made somewhat resilient to reduce interference with the fletching. A resilient arrow rest can be made by resiliently biasing (e.g., with a spring) a rigid rest into its support position, or by forming the rest using one or more resilient materials. In another example, a rigid arrow rest is arranged to facilitate passage of the fletching, e.g., by having a bifurcated or forked end of the rest that contacts the arrow, leaving a gap for passage of the fletching. The width of such a gap is limited to less than the arrow shaft diameter, and effectiveness of such an arrangement depends on proper alignment of the fletching of the nocked arrow with the gap.
Later arrow rests were developed using a "fall-away" design wherein the arrow rest is spring or resiliently biased downward (i.e., away from the arrow) and pulled upward to the arrow-supporting position by drawing the bow. This movement is typically achieved by connecting (e.g., with a connecting tie or similar structure) the arrow rest to one of the bow's cables, so that movement of that cable during drawing of the bow pulls the arrow rest up into its arrow-supporting position. The arrow rest is therefore in proper position to support the front end of the arrow when the bow is drawn. Upon firing the bow, movement of the bow's cables releases tension on the connecting tie and enables the arrow rest to nearly immediately fall away from the arrow in response to the bias on the rest. Such a fall-away rest moves out of the path of the arrow fletching, but typically only supports the arrow during a relatively small portion of its flight while it is still in contact with the draw cable. While the elimination of interference of the rest with the fletching is desirable, it is achieved at the expense of support of the arrow during only a very limited portion of its flight during firing of the bow.
It is therefore desirable to provide a fall-away arrow rest that substantially reduces or eliminates interference between the arrow fletching and the rest while nevertheless supporting the arrow shaft during a majority of its flight during shooting of the arrow by the bow.
A wide variety of arrow rests or arrow rest assemblies are available. One example is described in U.S. Pat. No. 6,044,832 entitled "Fall-away arrow rest assembly" issued Apr. 4, 2000 to Piersons.


A method for the exhaust dyeing of materials having hydroxy groups and materials containing carbonamide groups using a low salt content dye bath in conjunction with fiber reactive dyes exemplified by a dye of the following formula: ##STR1##

1. Technical Field
This invention is directed to the field of textile dyeing and in particular to the dyeing of textiles by the exhaust method using fiber reactive dyes containing the fiber reactive vinyl sulfone group.
2. Background
The exhaust method of dyeing is a batch method comprising the immersion of the textile goods in an aqueous solution of dye and various dyeing auxiliary chemicals. The goods are held in the dye bath for a predetermined time usually at an elevated temperature until the dye migrates into and fixes to the fiber. The exhaust dyeing method is well known in the art of coloring textiles; exemplary exhaust dyeing procedures are beck, jig, winch, jet and circulating liquor machine procedures.
In the exhaust dyeing method using fiber reactive vinyl sulfone dyes, one necessary auxiliary chemical is an electrolyte which is added to the dye bath to force the dye to migrate from the solution to the fiber. The most commonly used electrolyte is an inorganic salt such as sodium sulfate or sodium chloride. In exhaust dyeing procedures, this electrolyte is generally employed in amounts from about 20-50 grams per liter to about 100 grams per liter of dye bath with the amount of electrolyte being proportionally higher as the amount of dye employed in the dyeing increases. However, a few fiber reactive dyes are known which are used at reduced electrolyte concentration. After the dyeing process is completed, the exhausted dye bath solution is discharged to waste water treatment facilities for removal of electrolyte and other residual dye bath chemicals.
The present invention provides a method for the exhaust dyeing of textiles using a select class of dyes at significantly lower levels of electrolyte in the dye bath with the attendant reduction in raw materials costs, reduced chemical discharge to the environment and reduced waste water treatment costs. An additional advantage is that the process of the invention unexpectedly gives a higher dyeing efficiency as evidenced by the achievement of higher dye build up values.

Fiber reactive dyes - applications with low salt


A photoreceptor drum substrate comprising a drum of aluminum or aluminum alloy polished at the surface by centerless polishing. The photoreceptor drum substrate is manufactured by applying extrusion to a blank made of aluminum or aluminum alloy, then applying drawing to obtain a pipe material with less than 0.1% of bending to the entire length and satisfying the relation for wall thickness t, outer diameter .phi. and yield strength .sigma..sub.0.2, t.sup.2 .times..sigma..sub.0.2 /.phi..gtoreq.0.2 and then applying centerless polishing to the surface of the drum.

1. Field of the Invention
The present invention concerns a photoreceptor drum substrate used, for example, in copying machines and printers, as well a method of manufacturing the photoreceptor drum substrate.
2. Description of the Prior Art
For the photoreceptor drum substrate of this kind, an aluminum pipe has been used so far, for which high dimensional accuracy is required. For instance, in a photoreceptor drum substrate of 30 mm diameter, it is required to define the roundness thereof to less than 30 .mu.m and define the straightness to less than 30 .mu.m.
In a case of obtaining such a dimensional accuracy, the surface of the aluminum pipe (extruded and drawn pipe) is cut at a high accuracy by using a lathe and a diamond tool. Further, a method of decreasing the roundness and the straightness each to less than 30 .mu.m by applying extrusion and drawing on an aluminum pipe has been developed and practiced.
However, the known method of manufacturing the photoreceptor drum substrate described above involves the following problems.
First, in a precision cutting method for cutting an aluminum pipe by using a diamond tool or the like. The production cost for the photoreceptor drum substrate is increased remarkably and the productivity was poor.
On the other hand, in the precision drawing method of applying precision extrusion and drawing to an aluminum pipe at a high accuracy, although post-treatment such as cutting is unnecessary and the production cost is low, the aluminum pipe has to be cut short and the roundness of the aluminum pipe is worsened upon cutting to reduce the yield of products. Further, flaws caused by handling are liable to be formed at the surface of the aluminum pipe upon drawing.

Photoreceptor drum substrate and a method of manufacturing the same


A rolling line for the production of flat product includes a casting machine to continuously case a thin slab, a temperature maintenance and homogenization unit, a rolling unit a forming stand or roughing stand connected to the exit of the casting machine to reduce the thickness of the slab. The forming stand or roughing stand is configured to perform an adaptive reduction of the thickness of the cast slab smaller than or equal to about 65% at least as a function of the thickness, width and type of material of the finished flat product. The rolling unit is configured to perform a reduction of the reduction of the thin slab coming from the temperature maintenance and homogenization unit to a thickness comprised between about 1.2 mm and about 20 mm by three or fewer double rolling passes through the double rolling stand.

Rolling lines for strip are known which, in order to produce more than 800,000/1,000,000 tons/per year, start from the continuous casting of slabs and using continuous finishing trains with several rolling stands.
If thick slabs are cast, from 130 mm or more in thickness, the continuous finishing train is preceded by a reversing roughing train, whereas if the starting slab is a thin slab, with a thickness of less than 130 mm, for direct rolling, the train is formed simply by 5/9 continuous stands without a roughing train. For productions of less than 800,000/1,000,000 tons/per year a Steckel rolling mill with one or more reversing stands is commonly used, normally fed with slabs having a thickness from 150 to 250 mm.
A rolling line starting from thick slabs normally provides step-wise heating furnaces, a high pressure water de-scaler, a cropping shear, a Steckel reversing rolling train with one or two stands, a laminar cooling system and a winding unit.
Instead, a rolling line starting from thin slabs typically provides a casting machine of thin slabs, a system for the restoration, maintenance or homogenization of the temperature of the cast material, for example a tunnel furnace, a high pressure water de-scaler, a Steckel reversing rolling train with one or two stands, a laminar cooling system and a winding unit.
The rolling plant which starts from thin slabs, compared to that which starts from thick slabs, normally allows a saving, due to the fact that the cropping shear is not required, that the Steckel rolling stand or stands can have smaller diameters of the work rolls, about 740 mm instead of 810 mm: given the same compression, this allows to use rolling forces lower by 20-30%, with subsequent reductions in the sizes of the machine. Moreover, lower rolling forces also produce reduced rolling torque, and the size of the main motors will consequently have a smaller torque value, even less than 15-20%.
It is also known that rolling plants with reversing rolling trains of the Steckel type with one or more stands which use a slab with a thickness from 150 to 250 mm or more have limitations in productivity, in minimum thickness obtainable and in dimensional and surface quality of the final strip; the productivity is limited, given the great thickness of the starting slab, by the high number of rolling passes through the stand or stands and consequently by the long inversion down-times, with consequently long overall times from the beginning to the end of rolling; this also determines a lack of homogeneity of temperature along the strip, a high temperature loss and the formation of scale which negatively affect the final quality of the strip produced.
Moreover, the high temperature loss makes it impossible to roll thin slabs of finished product, for example from 1.8 to 1.2 mm or less.
Finally, the surface quality of the finished product is also affected by the use of the work rolls for the numerous passes of the cold head and tail ends and the consequent rapid deterioration of the surface of the rolls themselves. In order to reduce this disadvantage it is necessary to change the work rolls frequently, with consequent stoppages, compromising the factor of use and productivity of the plant.
A rolling line is known from document EP-A-0.625-383, consisting of a casting machine able to cast a slab of about 50 mm in thickness, a shearing unit, an inductor furnace, a tunnel furnace, a de-scaler, a two-stand rolling unit of the reversing type, or a continuous type with five stands in line, a cooling unit and a winding unit. The two-stand reversing rolling unit determines a reduction in thickness of the slab to a desired final value of about 1.5-2 mm by means of three double rolling passes. In this known solution, the thickness of the slab entering the reversing rolling unit is the same constant thickness of the slab which is cast. In this way, the known line is not adaptable according to the final thickness and width of the strip and of the type of steel, in order to obtain the final product with a minimum number of passes, because the thickness of the slab entering the reversing rolling unit cannot always be the ideal one; it is thus necessary to modify the thickness of the cast slab, which negatively influences the stability of the casting process. Moreover, in order to minimize the number of rolling passes, the known line has to have a high casting speed and therefore much more stressed working conditions.
Other casting lines and methods are disclosed in EP-A1-937.512, U.S. Pat. No. 4,675,974 and U.S. Pat. No. 6,182,490.
None of these documents, like EP'383, disclose the provision of a forming or roughing stand positioned immediately downstream the casting machine. The only forming or roughing stand provided upstream the Steckel rolling mill is disclosed in EP'512, but in this case the forming stand is located downstream the furnace, therefore not immediately downstream the casting machine. Moreover, the reduction provided in the roughing stand of EP'512 is designed to be up to 50%. None of these documents, therefore, allow to maintain low the number of sequential passes in the Steckel rolling mill for all the range of thicknesses that can be produced by the rolling line.
One purpose of the present invention is to achieve a rolling line with a Steckel rolling train with two reversing stands, and to perfect a relative method, which allows to reduce to a minimum the number of rolling and inversion passes and therefore reduce the total rolling time, with consequent increase in the productivity of the rolling mill, for the whole range of thicknesses that can be produced by the rolling line.
Another purpose is to reduce to a minimum the number of rolling passes, without imposing very stressed working conditions on the line, in particular with regard to the casting speed.
Another purpose of the present invention is to obtain a greater uniformity/homogeneity of the temperature along the strip being rolled and a lower overall temperature loss.
Another purpose is to increase the factor of use of the plant, increasing the working life of the work rolls.
Furthermore, another purpose of the present invention is to exploit to the utmost the great plasticity of the steel at the high temperatures which it has just after it has solidified, to carry out the roughing rolling of the product emerging from the continuous casting machine, so that it is thus possible to use smaller stands and hence with less power installed and with a considerable energy saving. The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.


Method to generate onboarding flow for application starts with on-boarding server receiving request from electronic device to activate application. On-boarding server determines whether request is initial request. Request is determined to be initial request when minimal set of information associated with user is not stored in on-boarding server. When request is determined to be initial request, on-boarding server signals to electronic device to display request for minimal set of information associated with user which includes at least one of: user identification, legal name, phone number, or email address. Minimal set of information associated with user is then received and stored in on-boarding server. On-boarding server signals to allow initial access to application. Signaling to allow initial access includes signaling that user requires access to payment processing hardware to process user's physical payment instrument. On-boarding server receives default payment information entered using payment processing hardware. Other embodiments are also described.

Currently, a number of applications that provide a service may be downloaded onto consumer electronic devices. For example, these applications include ridesharing applications like Uber™ and Lyft™, laundry and dry cleaning applications like Washio™, grocery delivery applications like Instacart™, etc. When signing up for these applications, the on-boarding process of the application requires the user to enter payment information before allowing the user to use the service it provides.
It has been shown that the request for the user's payment information at this stage of the on-boarding process is often an obstacle or a deterrent to potential users to finalize their signing up for the application. Further, when the user's enters their credit card payment information via the application, the interchange rate is higher because the user's card is considered to a card-not-present when it is charged.

This patent is subject to a terminal disclaimer.


A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

Climate change is driving electrification of transportation, and as a result, the need for batteries, such as lithium ion batteries (LIBs). Although LIBs are already ubiquitous in society, the total annual consumption is small compared to that which would be required for mass-market electric vehicle adoption. With a growing demand for LIBs, there is a growing demand for the chemicals from which they are produced, particularly battery-grade metal sulfates.
Nickel and cobalt sulfate battery chemicals are commonly produced by separately dissolving nickel metal and cobalt metal with sulfuric acid and conducting purification prior to crystallizing them as battery grade sulfates. This metal dissolution process is performed both by cathode manufacturers and by mining companies that have built sulfate production circuits at their refineries. The metal dissolving pathway from ore to battery requires the expensive steps of either electrowinning or hydrogen reduction to produce London Metal Exchange (LME) grade metal prior to dissolution. This pathway is a major contributor to the premium demanded for battery grade sulfates, mainly nickel sulfate, over metals prices. The industry is moving towards more direct production pathways from concentrate or intermediates to battery chemicals. For example, more direct pathways have already been developed for cobalt chemicals thanks to the maturity of the lithium-cobalt-oxide battery chemistry used in cell phones and electronics.
Further, current battery chemical production processes often include separation of cobalt and nickel via solvent extraction (SX), which enables production of individual battery grade sulfates that meet purity requirements. SX can be very effective in separating metals, but is a relatively complex unit operation, requiring multiple stages of extraction, scrubbing and stripping, and systems for organic treatment of aqueous discharge streams, crud removal, organic vapour recovery, and fire protection. These requirements result in substantial capital costs associated with a commercial scale SX operation. Depending on the number of SX circuits required, the direct costs associated with SX can be more than 30% of the refinery cost.
Further, producing battery-grade metal sulfates results in by-product salts for which disposal may be difficult. Often in current battery chemical production processes, SX and other impurity removal steps must be operated at a specific pH level to perform effectively. One of the bases generally used is sodium hydroxide because it is water soluble and available at high purities, allowing for effective pH control while minimizing scaling issues and minimizing the introduction of further impurities to the process. High consumption of sodium hydroxide, however, leads to the production of large quantities of sodium sulfate, which presents a serious impending environmental challenge. Sodium sulfate is a bulk commodity chemical product, but because of its low value (e.g., at 90-150 USD per tonne), transport costs frequently negate the benefit of its sale when no local demand exists. Further, the market for sodium sulfate is limited, and may be exceeded by the forecasted production resulting from new battery chemicals and battery precursor plants.
An improved process and method for producing crystallized metal sulfates is desired.

Process for producing crystallized metal sulfates


A thermal protector includes a header plate and a metal housing having an open end hermetically welded to an peripheral edge of the header plate. The housing is formed into a generally slender shape so as to be suited for mounting on end turns of a stator winding of a three-phase electric motor. A thermally responsive element includes a shallow curved portion at which the element changes states of curvature with snap action in response to different ambient temperatures. The thermally responsive element has two movable contacts secured to it to be disposed symmetrically about a center of the curved portion so that the movable contacts are engageable with and disengageable from fixed contacts respectively. A push piece is disposed in the housing to exert a pushing force on a normally convex side of the thermally responsive element. The pushing force is adjusted by deforming the outer surface portion of the housing for calibration of the operating temperature. The push piece includes a portion secured to an inner surface of the housing so as to correspond substantially to the deformed outer surface portion of the housing for calibration of the operating temperature.

1. Field of the Invention
This invention relates to an internal thermal protector for electric motors used in hermetic electrically-driven compressors, and more particularly to such an internal thermal protector for protecting three-phase motors against burnout.
2. Description of the Prior Art
As conventional thermal protectors of the above-described type, Japanese Patent Publication No. 56-130040A discloses a thermally responsive switch and Japanese Patent Publication No. 62-88232A discloses a thermally responsive snap action switch. These disclosed protectors are mounted on single-phase motors and comprise a thermally responsive element such as a bimetal having a central dish-shaped or otherwise, curved portion formed by drawing. The thermally responsive element has one end carrying a movable contact engaged with and disengaged from a fixed contact and the other end secured to an elastic plate. In determination of a contact pressure between the movable and fixed contacts and an operating temperature of the protector, both ends of the thermally responsive element are abutted against the fixed contact and a support respectively in an inoperative condition of the protector. In this state, a predetermined ressure is applied to a central convex portion of the thermally responsive element, so that the contact pressure and the operating temperature are determined. In these protectors, the thermally responsive element and parts around the element heat up when a current flows between terminals. The thermally responsive element changes its state of curvature with snap action when an ambient temperature is increased because of an abnormal condition of the motor or when the motor is in an overheat condition due to an overcurrent. Consequently, the movable contact secured to the one end of the thermally responsive element is disengaged from the fixed contact, thereby cutting off a current path.
Japanese Patent Publication Nos. 57-34623A, 1-105435A and 6-96649A disclose thermal protectors for a three-phase motor respectively. Each of these protectors comprises a generally circular thermally responsive element having a central dish-shaped or otherwise, curved portion formed by drawing. Two movable contacts and an elastic member are secured to the thermally responsive element so that points of securement form an imaginary substantially equilateral triangle. In determination of the contact pressure and the operating temperature of the protector, the movable contacts and the elastic member are abutted against fixed contacts and a support respectively. In this state, a predetermined pressure is applied to a central portion of the thermally responsive element which is convex at an ordinary temperature, so that the contact pressure and the operating temperature are determined. These three-phase motor protectors are connected to a neutral point of windings of a three-phase motor arranged in a wye configuration. Upon occurrence of an abnormal condition of the motor, the thermally responsive element changes its state of curvature in the same manner as described above about the thermal protectors for the single-phase motors, thereby opening the neutral point to cut off interphase current paths.
In the thermal protectors for the three-phase motors, the current is caused to flow through the thermally responsive element so that heat generated by the thermally responsive element is primarily used to operate the same. The two movable contacts and the elastic member are secured to the generally circular thermally responsive element so that points of securement form an imaginary substantially equilateral triangle. The three-phase thermal protectors are formed into a relatively flat configuration and has approximately equal longitudinal and lateral dimensions.
In each of the above-described motor protectors, the thermally responsive element carries the movable contact on the free end thereof and has the other end connected to the elastic plate and serving as a supported end, so that an excessive amount of stress is prevented from concentrating on the supported end. The elastic plate also serves as a heating element for compensating the heat generated by the thermally responsive element. However, in the case where the motor has a large rated current or where an operating temperature of the thermally responsive element is set at a large value, the elastic plate causes an annealing effect when serving as the heating element with its temperature being increased. Consequently, the performance of the elastic plate as an elastic member is reduced. Thus, the elastic plate cannot be used in the thermal protector when it is used for the motors of the high output type. A rigid heating element would be considered to be used instead of the elastic plate for the solution of the above-described problem. In this case, however, there is the possibility that an excessive stress may concentrate on the supported end of the thermally responsive element, resulting in variations in the operating temperature thereof. This entails a problem.
The elastic plate can be twisted even when the thermally responsive element is inclined relative to the fixed contacts to some extent in assembling. Consequently, the contact pressures can be equilibrated between the two pairs of contacts without being adversely affected by the inclination of the thermally responsive element in the three-phase thermal protector using the elastic plate. On the other hand, the above-described equilibrating adjustment cannot be carried out when the thermally responsive element is supported by a rigid member. Accordingly, separate contact pressure adjusting mechanisms need to be provided for the respective pairs of contacts, or the two pairs of contacts need to be assembled with such a high-level accuracy that the two pairs of contacts are simultaneously engaged and disengaged and that the contact pressures are rendered equal. This entails another problem.
The conventional three-phase thermal protectors include the generally circular thermally responsive element and are formed to have a relatively flat configuration and approximately equal longitudinal and lateral dimensions, as described above. Particularly when the protector is bound to end turns of the motor winding with strings, the protector thus mounted becomes unstable since the protector has a larger width than the end turns of the winding. The size of the electrically-driven compressor has recently been reduced and the diameter of the motor used in the compressor has also been reduced accordingly. The overall size of the conventional protector needs to be reduced when the width thereof is rendered smaller than that of the end turns of the winding. However, this reduces a current capacity of the protector and renders the manufacture of the protector difficult. This entails further another problem.
Furthermore, a work for attaching an insulating covering to the conventional thermal protector for the insulation thereof is troublesome since the protector is formed to have a relatively flat configuration and approximately equal longitudinal and lateral dimensions. A receptacle of the protector usually serves as an electrically conducting section. A failure such as short circuit occurs when the receptacle is brought into contact with another electrically conducting part or member. Accordingly, the thermal protector needs to be covered by the insulating covering such as a polyester tube. The polyester tube having an inner circumference larger than an outer circumference of the protector is put onto the protector to cover the latter. The tube is fixed to the surface of the protector by heat shrinkage. Since a polyester film does not have a large coefficient of heat shrinkage, the difference between the outer circumference of the protector and the inner circumference of the polyester tube is small. Accordingly, the generally cylindrical polyester tube needs to be deformed to a large extent in order to be fitted with the protector when the protector is formed to have a relatively flat configuration and approximately equal longitudinal and lateral dimensions. Thus, positioning the polyester tube is difficult and the work for attaching the tube to the protector is troublesome. This entails further another problem.


A method is provided for manufacturing a holographic medium by recording holograms in transmission geometry, and applying a reflective layer to one side of the holographic recording material after recording is completed (alternatively, for example, the playback system may contain a reflective surface or mirror). For readout, the reference beam is incident to the media from a side opposite the reflective layer. This beam propagates through the media to the reflective layer on the opposite side, and is reflected back through the media for readout of the transmission hologram. The diffracted hologram signal also exits the media on the side without the reflective layer, where it can be recovered by a detector on the same side as the laser source. Alternatively, the readout reference beam is positioned so that the incident beam reads out the hologram, and both the reference beam and diffracted hologram are reflected back through the media.

1. Field
The invention relates generally to holographic data storage media and systems, and more particularly to methods and systems for recording and/or reading holographic storage media having a reflective layer for readout (or playback).
2. Description of Related Art
Holographic data storage systems store information or data based on the concept of a signal beam interfering with a reference beam at a holographic storage medium. The interference of the signal beam and the reference beam creates a holographic representation, i.e., a hologram, of data elements as a pattern of varying refractive index and/or absorption imprinted in a volume of a storage or recording medium such as a photopolymer or photorefractive crystal. Combining a data-encoded signal beam, referred to as an object beam, with a reference beam can create the interference pattern at the storage medium. A spatial light modulator (SLM) or lithographic data mask, for example, may create the data-encoded signal beam. The interference pattern induces material alterations in the storage medium that generate the hologram.
The formation of the hologram in the storage medium is generally a function of the relative amplitudes and polarization states of, and phase differences between, the signal beam and the reference beam. The hologram is also dependent on the wavelengths and angles at which the signal beam and the reference beam are projected into the storage medium. After a hologram is created in the storage medium, projecting the reference beam into the storage medium interacts and reconstructs the original data-encoded signal beam. The reconstructed signal beam may be detected by using a detector, such as a CMOS photo-detector array or the like. The recovered data may then be decoded by the photo-detector array into the original encoded data.
A basic holographic system is illustrated in FIG. 1. The holographic storage system includes a light source 110, for example, a laser for providing a coherent beam of light. A beam splitter 114 is positioned to split the laser beam into an object beam and a reference beam. The object beam is directed to an SLM or data mask 116 where it is encoded with information as a two-dimensional image and directed to the recording storage medium 124 by mirror 118 and lens 120 where it interferes with the reference beam directed via mirror 130. A complex interference pattern is recorded in the storage medium 124 where the object beam and reference beam interact. After a first image or layer is recorded, the system may be modified to enable additional images to be recorded in storage medium 124. For example, by modifying the angle and/or wavelength of the reference beam, successive images may be recorded in the storage medium 124.
A particular image may be retrieved from recording medium 124 with a reference beam similar to the original reference beam used to store the image. The light is diffracted by storage medium 124 according to the stored hologram and the two-dimensional image that was stored in recording medium 124 is directed by lens 126 to photo-detector array 128.
Two basic holographic system geometries include transmission and reflection geometry. In transmission geometry, shown in FIGS. 1 and 2, the diffracted light from the hologram exits the media from the opposite side from the incident reference beam. The light source, e.g., a laser source, and the camera for detection are therefore disposed on opposite sides of the media. For recording at different spatial locations on the media, such systems are typically limited to moving the media because of the complexity of synchronously moving the laser source and camera on both sides of the media, if the media were kept stationary.
In reflection geometry, shown in FIG. 3, the diffracted light from the hologram exits the media from the same side as the incident reference beam. Because the laser source and camera are on the same side of the media in this case, this geometry is more flexible for either moving the media or moving the laser source and camera (e.g., together on a shared head or stage) in order to access different locations on the media.
Holograms recorded in reflection geometry, however, are generally more sensitive than transmission geometry holograms to effects such as shrinkage or anisotropic thermal expansion of the media. Such media distortion leads to detuning of the beam angles needed to properly read out the holograms, and are about an order of magnitude larger for reflection geometry holograms than for transmission geometry. For high bandwidth object beams, which span a wide angular range, different parts of the image can have significant variation in detuning angles, so that it may not be possible to fully recover the entire data page. The magnitude of the variation is smaller for transmission geometry, and furthermore, it can be compensated almost fully with a proper combination of readout beam angle and wavelength adjustments. For reflection geometry, even with an optimal adjustment of angle and wavelength, the entire data page may not be recoverable.
One architecture variation which has been proposed previously is to use media with a reflective layer on one side, such as shown in FIG. 4. Such an example is described in Saito, K. and Horimai, H. (1998) "Holographic 3-D Disk using In-Line Face-to-Face Recording", Optical Media Laboratory, Sony Corporation, pp. 162-164, the entire content of which is hereby incorporated by reference. This has a similar benefit of reflection geometry, i.e., having all components on one side of the media; however, the reflective layer is present for both recording and readout. This has the consequence that during recording, the hologram area has a mixture of incident and reflected beams for both the reference and object beams. As a result, both transmission and reflection hologram components are recorded in the same volume. As described earlier, under shrinkage or thermal expansion, the reflection and transmission hologram components will behave differently with different degrees of detuning. This can lead to interference and distortion between the transmission and reflection components of the reconstructed hologram.
Another prior art variation includes the use of a reflective layer together with a polarization shifting layer. Such an example is described, for example, in U.S. Pat. No. 6,721,076, to King, B., Anderson, K., and Curtis, K., entitled "SYSTEM AND METHOD FOR REFLECTIVE HOLOGRAPHIC STORAGE WITH ASSOCIATED MULTIPLEXING TECHNIQUES," the entire content of which is hereby incorporated by reference. In this case, both reflected beam polarizations are rotated upon reflection, so that transmission hologram components are recorded by both the incident and reflected beam pairs, but no reflection hologram components are recorded. This avoids the possible negative interaction between transmission and reflection components of the reconstructed hologram, but generally benefits from the incorporation of a potentially costly polarization shifting layer in the media fabrication. Also, even though no holograms are recorded between beam components with crossed polarizations, the presence of light from the reflected beams in the same volume where the hologram between the incident beams is being recorded, and vice versa, may reduce the modulation depth of the holograms, resulting in wasted dynamic range of the media.

Holographic storage device having a reflective layer on one side of a recording layer


A mobile device which supports apparatus for site imaging while in transit is disclosed. The mobile device comprises a plurality of wheels, an imaging unit having at least one camera and supported above the head of an operator, a control unit for monitoring and controlling operation of each camera and of generated image data so as to produce an interactive movie, a steering device for navigating the mobile device within the site, a measuring device for measuring the relative displacement of the mobile device, a computer for determining the relative location and orientation of the mobile device within the site and for processing data, and a monitor. In one embodiment, two of the wheels are self-aligning caster wheels, and a mechanism and method for preventing drifting during the initial advancement of the mobile device are provided. A rotating mechanism is actuated until each caster wheel achieves a trailing position.

Virtual movies are widely used for a variety of purposes, such as exhibitions, remote guidance and touring of places, education, training, electronic games, etc. Some of such movies are animated, and some others are real, in the sense of involving real frames that are photographed within a tangible site. The present invention relates to the latter case, i.e., to the case where the preparation of a virtual and interactive movie enables a user to explore a tangible site.
For example, there are some cases in which it is desired to allow a user to view a filmed representation of a site, and navigate interactively thereinafter within the site. More particularly, it is desired to produce an interactive movie enabling the user to view a desired region of a site in any selected direction, while viewing continuously changing actual images of the selected region that may be optionally combined with computer generated interactive or non-interactive events or objects.
In another, more particular example, it is desired to produce a virtual interactive movie for training personnel so that they may be familiarized with a specific site, while being provided with essential and comprehensive information concerning the site, such as its layout, its appearance, location of rooms and equipment therein. Moreover, it could be beneficial to integrate a simulated event, for example, a fire, into the movie so that the personnel may learn how to deal with some emergency procedures.
Such virtual interactive movies that enable people to navigate within a tangible site can also be used for marketing purposes, for example, allowing viewers to interactively explore sites such as real estate properties, hotels, etc.
The preparation of a virtual, interactive movie which enables navigation within a site is generally a very complicated task, and it involves a substantial effort, requiring professional and lengthy filming and editing. Also, the results are generally not so satisfactory, being far from providing to the user a real navigating and exploring feeling.
International Patent Publication No. WO2004/049263 filed on Nov. 24, 2003 by same applicant discloses a method and apparatus for producing a virtual movie for the purpose of exploring a tangible site. According to said application, a movable platform supports all the system components. The movable platform is moved within the site, while measuring the x,y coordinates and the orientation (angle), producing site nodes (as defined in said application), acquiring site images, up to 360° field of regard, and performing additional processing tasks including the processing and preparation of the final movie.
Such a movable platform, as described in WO2004/049263 can generally perform this task. However, there are some problems associated with operating such platform, as follows:                a. When the system acquires images from the rear of the platform, the operator has to hide from view of each of the cameras in order not to appear in the acquired images.        b. The platform, which supports all the system components, is heavy, and the operator has to apply a significant force in order to move the platform and operate the system within the site.        c. As the platform has to smoothly move along the site, which generally includes a narrow passageway, such as a door, or negotiate around an obstacle, this task becomes even more complicated.        d. Additionally, as in many cases in which the system has to be transported from one site to another, it is important to have a relatively light weight platform, which also has a small volume.        e. Moreover, the movable platform drifts as the supporting caster wheels return to a normal trailing position, following a change in direction, resulting in a bothersome wobbling sensation in the produced virtual movie.
It is therefore an object of the present invention to provide a mobile device which supports apparatus for imaging a site to be displayed in an interactive virtual movie and which overcomes all the above drawbacks.
It is an additional object of the present invention to provide a mobile device which is of relatively small dimensions, of relatively light weight, and with good maneuverability.
It is an additional object of the present invention to provide an operator with means for conveniently directing the mobile device to a desired region of a site, and means for conveniently controlling the operation of the imaging apparatus.
It is yet an additional object of the present invention to provide the mobile device with means for preventing drifting thereof during advancement between regions of the site, to increase the quality of the interactive movie being produced.
Other objects and advantages of the invention will become apparent as the description proceeds.

Mobile device suitable for supporting apparatus for site imaging while in transit


A rotatable magnet configuration for use in a magnetron sputtering system for obtaining a desired sputter target erosion profile and for obtaining a sputtered film on a substrate having a desired film characteristic, such as uniformity of thickness, and a method of designing such a magnet configuration are disclosed. The disclosed design and method compensate for the discrepancy between the between the actual position of the magnet and the "effective" position of the magnet as measured by a static erosion profile obtained holding the magnet stationary. The method shown describes how to adjust the actual shape of the magnet to obtain a desired effective shape that will produce a predetermined erosion profile in the sputter target. In addition, the disclosure describes how to determine an optimal erosion profile to produce a sputtered film having a desired characteristic.

Physical vapor deposition by sputtering is a well known process that has found widespread application in the fabrication of integrated circuit semiconductor devices. In semiconductor device fabrication, a large number of integrated circuit devices are normally formed on a thin, generally circular semiconductor substrate referred to as a wafer. Integrated circuit device fabrication involves a large number of processing steps, with sputtering typically being used to provide metallization layers and interconnects between device layers. Most commonly, sputtered aluminum is the material used for these purposes. Modern semiconductor processing has also seen the increased use of sputtered tungsten, tungsten silicide, titanium, titanium nitride and other films.
A magnetron sputtering source is capable of high rate sputtering and represents an enormous improvement over devices forming thin films based on diode sputtering or evaporative techniques. Magnetron sputtering sources are routinely used by the semiconductor processing industry to coat semiconductor wafers during the manufacture of integrated circuits.
In magnetron sputtering a plasma is formed in a low pressure inert gas by the application of a suitable voltage. The plasma is confined to a region near a sputter target, which is made of the material to be sputtered and which usually serves as the cathode of the system. A magnetic field, typically having field lines which loop through the sputter target surface, restricts the trajectories of the electrons in the plasma, thereby intensifying and confining the plasma. Ions in the plasma bombard the sputter target dislodging atoms of the target material which are then deposited on a substrate.
In recent years wafer sizes have continually increased, and now the use of eight-inch diameter wafers is common in the industry. Large wafer sizes permit a larger number of integrated circuit devices to be grown on a single substrate. However, larger wafer sizes impose greater demands on sputtering systems. For example, one requirement of a sputtering system used in semiconductor processing is that it deposit a layer of uniform thickness over the entire wafer surface. (Hereinafter the term uniformity will be used in connection with the thickness of the deposited film unless the context suggests otherwise.) Lack of uniformity may result in lowered device yield (i.e., the percentage of devices which meet operating specifications) and/or variations in device performance. Larger wafer sizes make it more difficult to achieve very demanding levels of uniformity. Likewise, the trend towards ever smaller integrated circuit device geometries has required that even greater levels of sputtered film uniformity be achieved.
Other sputtered film characteristics are also quite important to integrated circuit device manufacturers. For example, as noted above, sputtered conductive material is frequently used to form interconnects between device layers. Forming interconnects involves uniformly filling small diameter holes, called vias, in the surface of the wafer. As integrated circuit device geometries have shrunk, the difficulty in filling vias with sputtered material has increased appreciably. Step coverage, or the ability of the sputtered film to evenly conform to angular features on the wafer surface is, likewise, another important film characteristic.
An earlier approach to improving the uniformity and step coverage characteristics of a sputtering system is to sputter from two concentric targets. For an example of this approach see U.S. Pat. No. 4,606,806 which describes a sputtering source sold by the assignee of the present invention under the trademark ConMag.RTM. II. In the ConMag.RTM. II sputtering source each of the sputter targets has a unique shape and its own separate power supply enabling separate control over the sputtering rate from each target.
A number of commercially available sputtering sources use planar sputtering targets. Early designs, wherein the planar magnetron sputtering device used a stationary magnet had practical shortcomings, the most serious of which is that the plasma discharge is localized and erodes a narrow groove in the target in the vicinity of the greatest magnetic field strength. This localized erosion generates a non-uniform distribution of sputtered atoms from the target and a film with non-uniform thickness on the semiconductor wafer. The non-uniform erosion of the sputter target leads to inefficient target utilization. Given the high cost of the sputter targets used in semiconductor manufacture, it is important to obtain the greatest possible target utilization that is consistent with the need for sputtered film uniformity and other required sputtered film characteristics.
Numerous attempts, some partially successful, have been made to modify the planar magnetron source to extend the target erosion and to make the distribution of sputtered atoms more uniform. Attempts have been made to spread out the erosion over a larger surface area using extended magnetic fields. The magnets required for such an approach are large and complicated, and it is difficult to assure that the properties of the magnetron do not change as the target erodes away. The resulting erosion pattern is thus difficult to predict.
U.S. Pat. No. 4,444,643, which is incorporated herein by reference, describes a sputtering device which includes a mechanically rotated annular permanent magnet assembly. The rotation of the permanent magnet assembly causes erosion over a wider area of the target. A version of the sputtering source described in the '643 patent has been sold commercially by the assignee of the present invention under the trademark VersaMag.TM.. This source relies on a rotating magnet mounted behind the target for moving the plasma over the face of the target. Rotation of the plasma was introduced for the purposes of improving uniformity and step coverage, as well as improving the uniformity of target erosion so that targets are more efficiently utilized.
The VersaMag sputtering source, while a significant improvement over planar magnetron sources employing stationary magnets, nonetheless did not produce truly uniform sputtered film nor uniform target utilization. Thus, efforts have been made to develop improved rotating magnet designs for use with planar targets. (The term "planar target" is intended throughout this specification to be descriptive of the sputter target surface before it is eroded. Those skilled in the art will recognize that after the target has been eroded it may no longer have a planar surface.)
One direction that has been taken by those seeking to improve the design of rotating magnets used with planar magnetron sputtering sources has been the used of closed-loop, generally heart-shaped magnet configurations. Such magnet configurations typically employ an array of magnets which are centered along a line defining a heart-shaped, closed loop.
One such arrangement is described in U.S. Pat. No. 4,872,964, entitled "Planar Magnetron Sputtering Apparatus And Its Magnetic Source", issued Oct. 10, 1989 to Suzuki, et al. Suzuki, et al., review the shortcomings of a sputtering source of the type described in the '643 patent and describe a heart-shaped rotating magnet array which is said to produce more uniform target erosion. However, the Suzuki, et al., patent overly simplifies the mathematics of the situation and, therefore, does not fully teach how to obtain truly uniform target erosion. In apparent recognition of this shortcoming, Suzuki, et al., describe the need to adjust the magnet array, after it has been laid out in accordance with their mathematical analysis, "to get more uniform erosion after a test run of the sputtering apparatus." (Col. 5, lines 27-28.) Unfortunately, Suzuki, et al., do not teach any methodology for making the necessary adjustments. The teachings of Suzuki, et al., are directed to how to obtain uniform erosion of the target. While uniform target erosion is important, the characteristics of the sputtered film, such as uniformity, are of greater importance to integrated circuit device manufacturers. In many instances, as will be described below, a non-uniform target erosion pattern improves the uniformity of the sputtered film.
Another sputtering source having a heart-shaped magnet arrangement is described in Japanese Patent Application Publication (Kokai) No. 62-211,375 entitled "Sputtering Apparatus", published Sept. 17, 1987. That patent prescribes the use of a heart-shaped closed loop magnet having a curve defined by the equation r=l-a+2a.vertline..theta..vertline./.pi., (for -.pi.23 .theta..ltoreq..pi.); where the center of the sputter target is located at the origin of a polar coordinate system, r is the distance between the origin and a point on the curve defining the magnet centerline, l is the distance between the center of the heart and the cusp of the heart, and a is the distance between the center of the heart and the center of the target. No derivation is given as to how the inventors arrived at this equation, and it appears to be a compromise between the annular-shaped magnet of the '643 patent and the heart-shaped magnet of the '764 patent. As discussed in the '375 application, a magnet having the prescribed curve will not produce uniform erosion. Moreover, the '375 application does not teach how to obtain any arbitrarily selected erosion profile.
U.S. Pat. No. 4,995,958, entitled "Sputtering Apparatus With A Rotating Magnet Array Having A Geometry For Specified Target Erosion Profile", issued Feb. 26, 1991, to Anderson, et al., also assigned to the assignee of the present invention, describes another generally heart-shaped, closed-loop magnet array for use in a planar magnetron sputtering source. The Anderson, et al., patent, which is hereby incorporated by reference, includes a rigorous mathematical analysis to show how to construct a closed-loop rotating magnet to realize a predetermined erosion profile to thereby achieve, for example, highly efficient target material utilization and high deposition rates. It is noted that the invention of the '958 patent is readily adapted to use in a VersaMag.TM. sputtering source.
Among other things, the '958 patent describes the shortcomings of the aforementioned Suzuki, et al., patent and the teaching of the '375 Japanese patent application, showing how each reference fails to provide a teaching which truly enables one to obtain uniform erosion of a planar sputter target. Importantly, FIGS. 12A-12E of the '958 patent, and the related text, clearly show that minor changes in the shape of a heart-shaped magnet may lead to very dramatic differences in the resulting erosion pattern of the sputter target. (It is believed that this is also shown by the '375 application.) Given the demonstrated fact that minor perturbations of the shape of a heart-shaped magnet may cause significant changes in the resulting target erosion profile, it becomes quite difficult to optimize the shape empirically. Thus, Anderson, et al.'s, mathematical analysis is a highly significant teaching in making heart-shaped, closed-loop magnets practically useful.
A closed-loop magnet configuration of the type described in the '958 patent has the additional advantage of being easily adjustable so that the shape of the magnet array, and therefore the characteristics of the sputtering source, can be changed without great difficulty or expense. As described in that patent, a plurality of magnets are held in position by two iron keepers, or pole pieces, which define the shape of the closed loop. Replacement and/or adjustment of the iron keepers to provide a different closed-loop configuration is a relatively simple matter. In this manner it is possible to use one source for different purposes, or to adjust the source as needs change.
A prime objective of the closed-loop rotating magnet of the '958 patent was to achieve better target utilization efficiency, normally an important objective given the high cost of sputter targets, and to achieve high deposition rates, another important factor due to the demand for ever greater system "throughput". As noted above, the need for greater sputtered film uniformity generally outweighs the need for efficient target utilization and deposition rate. Accordingly, the Anderson, et al., patent provides the basis for obtaining any arbitrary target erosion profile. It is noted, however, that the Anderson et al., patent provides no instruction as to how to determine what erosion profile to use under a given set of conditions to maximize sputtered film uniformity or other sputtered film characteristics.
As described therein, the mathematical analysis provided by Anderson, et al., is inapplicable at two areas of the heart, i.e., in the area near the "tip" of the heart, which is defined herein to mean the generally convex portion of the loop farthest away from the axis of rotation, and in the area near the "cusp" of the heart, which is defined herein to mean the generally concave portion nearest the axis of rotation and which lies between the two lobe-shaped portions of the heart. As a result of the inapplicability of the Anderson, et al., teaching to the region of the cusp of the heart, the designs they show leave the very center of the target unused, and are not optimized for best utilization of the sputter target edge. Moreover, the analysis of the '958 patent is based on the assumption that the magnet has uniform strength at all point along the loop, i.e., the sputtering intensity is the same at all points. In other words, the total quantity of material sputtered per unit length of the magnet is a constant. It has been observed that this assumption is not correct.
It is noted that all of the heart-shaped designs shown by Anderson, et al., Suzuki, et al., and the '375 application are symmetrical about a line which passes through the tip, the cusp, and the axis of rotation of the heart. The symmetry of the Anderson, et al., designs is due to the fact that their method of generating a heart-shaped magnet is by forming a spiral-like shape over 180.degree. (i.e., over one half of a polar coordinate system) and then mirroring this shape to close the loop over the remaining 180.degree.. However, as used herein, the term heart-shaped does not require that there be two strictly symmetrical halves. As will be described below, there may be circumstances when an asymmetrical heart-shaped magnet is desired. Likewise, as used herein, the term heart-shaped, does not require that the heart have a noticeable "tip". It has been found that there are advantages to using a design wherein the region farthest from the axis of rotation and generally opposite the cusp forms an arc of a circle. As used herein, the term "heart" implies that there is a cusp-like transition between two lobes. The cusp-like transition may be smoothed for design convenience.
Finally, it has been discovered that there are discrepancies between the position of the magnetic field adjacent to the sputter target surface as predicated by Anderson, et al., and as empirically measured. As noted above, even minor changes in the shape of the magnetic field generated by a heart-shaped magnet may result in significant variations in the erosion profile obtained.

Sputtering apparatus with a magnet array having a geometry for a specified target erosion profile


The invention relates to a quantum dot. The quantum dot comprises a core including a semiconductor material Y selected from the group consisting of Si and Ge. The quantum dot also comprises a shell surrounding the core. The quantum dot is substantially defect free such that the quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent.

Over the past several years, there has been an increasing interest in exploiting the extraordinary properties associated with quantum dots. As a result of quantum confinement effects, properties of quantum dots can differ from corresponding bulk values. These quantum confinement effects arise from confinement of electrons and holes along three dimensions. For instance, quantum confinement effects can lead to an increase in energy gap as the size of the quantum dots is decreased. Consequently, as the size of the quantum dots is decreased, light emitted by the quantum dots is shifted towards higher energies or shorter wavelengths. By controlling the size of the quantum dots as well as the material forming the quantum dots, properties of the quantum dots can be tuned for a specific application.
Previous attempts at forming quantum dots have largely focused on quantum dots of direct band gap semiconductor materials, such as Group II-VI semiconductor materials. In contrast to such direct band gap semiconductor materials, Group IV semiconductor materials such as Si and Ge have energy gaps, chemical properties, and other properties that render them more desirable for a variety of applications. However, previous attempts at forming quantum dots of Si or Ge have generally suffered from a number of shortcomings. In particular, formation of quantum dots of Si or Ge sometimes involved extreme conditions of temperature and pressure while suffering from low yields and lack of reproducibility. And, quantum dots that were produced were generally incapable of exhibiting adequate levels of photoluminescence that can be tuned over a broad spectral range. Also, previous attempts have generally been unsuccessful in producing quantum dots of Si or Ge that are sufficiently stable under ambient conditions or that can be made sufficiently soluble in a variety of matrix materials.
It is against this background that a need arose to develop the quantum dots and methods for forming quantum dots described herein.

Quantum dots of group IV semiconductor materials