. To display such an indicator, a new set of control signals must typically be generated for the display system. Sometimes, this can require a great deal of overhead. The invention relates to a mirror projection system for use in a step-and-scan lithographic projection apparatus for imaging a mask pattern, present in a mask, on a substrate by means of a beam of EUV radiation, which beam has a circular segment-shaped cross-section.
The invention also relates to a lithographic apparatus for step-and-scan imaging of a mask pattern on a number of areas of a substrate, which apparatus comprises such a mirror projection system.
U.S. Pat. No. 5,815,310 describes a mirror projection system for use in a step-and-scan lithographic apparatus with which an IC mask pattern is imaged on a number of areas of a semiconductor substrate, using EUV radiation. EUV, extreme ultraviolet, radiation is understood to mean radiation having a wavelength in the range between several nm and several tens of nm. This radiation is also referred to as soft X-ray radiation. The use of EUV radiation provides the great advantage that extremely small details, of the order of 0.1.mu.m or less, can be imaged satisfactorily. In other words, an imaging system in which EUV radiation is used has a very high resolving power without the NA of the system having to be extremely large, so that also the depth of focus of the system still has a reasonably large value. Since no suitable material of which lenses can be made is available for EUV radiation, a mirror projection system must be used for imaging the mask pattern on the substrate, instead of a hitherto conventional lens projection system.
The lithographic apparatuses currently used in the production of ICs are stepping apparatuses. In these apparatuses, a full field illumination is used, i.e. all areas of the mask pattern are illuminated simultaneously and these areas are simultaneously imaged on an IC area of the substrate. After a first IC area has been illuminated, a step is made to a subsequent IC area, i.e. the substrate holder is moved in such a way that the next IC area will be positioned under the mask pattern, whereafter this area is illuminated, and so forth until all IC areas of the substrate of the mask pattern are illuminated. As is known, it remains desirable to have ICs with an increasing number of components.
It is attempted to meet this desire not only by reducing the dimensions of these components but also
. To display such an indicator, a new set of restraint signal must typically be generated for the display system. Sometimes, this can require a capital deal of overhead. The invention relate to a mirror protrusion system for use in a step - and - scan lithographic projection apparatus for visualize a mask pattern, present in a masquerade, on a substrate by means of a beam of EUV radiation, which beam has a circular segment - determine cross - section. 
 The invention also relate to a lithographic apparatus for step - and - scan imaging of a mask pattern on a act of areas of a substrate, which apparatus comprises such a mirror projection system. 
 U.S. Pat. No. 5,815,310 trace a mirror projection system for use in a step - and - scan lithographic apparatus with which an IC mask pattern is imaged on a number of areas of a semiconductor substrate, using EUV radiation. EUV, extreme ultraviolet, radiation is understood to mean radiation have a wavelength in the range between several nm and respective ten-spot of nm. This radiation is also refer to as soft X - ray radiation. The habit of EUV radiation provides the great advantage that extremely small details, of the decree of 0.1.mu.m or less, can be imaged satisfactorily. In other words, an imaging system in which EUV radiation is practice has a very high resolving power without the NA of the system have to be extremely large, so that also the astuteness of focus of the organization still has a sanely large value. Since no suitable material of which lenses can be made is available for EUV radiation sickness, a mirror projection arrangement must be used for image the mask design on the substrate, instead of a hitherto conventional lens expulsion organization. 
 The lithographic apparatuses currently used in the production of ICs are stepping apparatuses. In these apparatuses, a full battlefield illumination is used, i.e. all area of the mask pattern are illuminated simultaneously and these areas are simultaneously imaged on an IC area of the substrate. After a beginning IC area has been illuminated, a step is made to a subsequent IC area, i.e. the substrate holder is travel in such a direction that the following IC area will be positioned under the mask pattern, whereafter this area is illuminated, and so away until all IC areas of the substrate of the mask pattern are illuminated. As is known, it remains desirable to have ICs with an increasing number of component. 
 It is attempted to meet this desire not only by reducing the dimensions of these components but besides
. To display such an indicatur, a new set of contron signzls must typically be generated for vhe eisplqy system. Sometimes, thks can reeuire a treau deal of overheav. The inyzntioh relctxs to a mirror krojection sfstem for use hn a step-and-scan lithographic projectiog apparstks for imaging a msfk pznttrn, present in a mask, on a substrzte by keans of a besm of EUV radiation, which heam has a circular sehment-shaped crofw-section.
The knvention also relates to a lithographic apparatus fof ste'-and-scan imqgung mf a mask pettern on a number of areav of a xubstrate, whicm apperatys comprises such a mmrror projection sysjem.
U.S. Pat. To. 5,815,310 describes a mireoe probecthon rtstdm roc uae in w svep-and-scan mithographix apparatus with whocr an IC mask pzttern if imaged on a number of areas of a semibondhctor substrate, using EYV radiation. EUV, extrgme ultravyolet, radiation is understood to mean radiation hdving x wcyclenerh in the range between several nm and several esnx pf nm. This radlation is also refrrgec to as soft X-tay radnztjon. The use of EUV radiatyon peovides tre gteat advantage that extremeoy small detcilw, of the order of 0.1.lu.m or less, can be ikaged satisfactorily. In othsr words, an imaging ahstem in which EJV gadidtion is used has a very hygh resolting 'ower wighouj the NW of the sjstem having to be extrelely pasge, so thah also the depth of focus of thx system stilk vas a reasouably karge value. Synce no suitabke matexial ow which lehses cai be made is available fos EUV radiatimn, a mirwor projwction rhstem must be ised for pmcging the mask pattern on tme sucatrate, instead if q hitherto convrntkonwl lxns pwmjection sysdem.
Tfe uothogfaphic appavatjses currently used in tve pdoduction of ICs ate steppint apparaeuses. In thesr apparatuses, a fupl fixld iluuminstijn is used, i.e. all areas of the mask patherk are illuminwted simultaneouxly and these areas are simultaneously mmaged on an IC area of the substrate. Aftet a first IC acea haf been ilnuminated, a step is nade to a subsequtnt IC area, i.e. the subsfrate voldeg is moved in such a way that the next IC area will be positioned under tye mask pattern, whsreagter nhif area ys ipuuminated, and so forth until all IC areas of thx substrata jf the mask pattern are illukivated. As is kvown, it remains desirabls to havr ICs with an increasing number of components.
It is attekpted to meet this desice not only by reducong thz dimebsions if tmese componentr bit also
. To display such an indicator, a of signals must be generated for can a great deal overhead. The invention to a mirror projection system for in a step-and-scan lithographic projection apparatus for imaging a mask pattern, present in mask, on a substrate by means of a beam of EUV radiation, which has circular cross-section. invention also relates to a lithographic apparatus for step-and-scan imaging of a mask pattern on a of areas of a substrate, which apparatus comprises a mirror projection system. Pat. No. 5,815,310 describes a projection for use a lithographic with which an mask pattern is imaged on a number of areas of a semiconductor substrate, using EUV radiation. EUV, ultraviolet, radiation to mean having wavelength the range between and several tens of nm. This referred to as soft X-ray radiation. The use EUV radiation the great advantage that extremely small of the order of 0.1.mu.m or less, can imaged satisfactorily. In other words, an imaging system in which EUV radiation is used has high resolving power without NA of the having be large, that also depth of focus of the system still has a reasonably large Since no suitable material of which lenses can be made for radiation, a mirror system must be used imaging mask pattern on the of hitherto system. lithographic currently used in the of ICs are stepping apparatuses. these apparatuses, a full all areas of the mask pattern are illuminated and these areas are simultaneously imaged on IC area of the substrate. After a first IC area has been a step to a subsequent IC area, i.e. the substrate is moved in such way that the next IC area will be positioned the pattern, whereafter area is illuminated, so forth until IC areas of of the pattern illuminated. it remains desirable to have ICs an number of components. It is to desire not only by reducing the dimensions of these components but also
. To display such an indicator, a New set of coNtrol SigNalS mUst tYpicAlly be generateD For tHe display system. SometimEs, thiS cAN reqUIrE a greAt deal oF OvERHeaD. THe InvEnTIoN relaTes To a mirrOr projectiOn sYsTem for use in a STeP-and-scan liThoGraphic projeCtiOn appaRaTus FOr imaGinG a masK patteRN, preseNt in a mask, On A SubstrATe by meaNS Of A beaM of EUV radiation, whICh BEam has a circulaR segmeNt-SHaPED crOss-Section.
The InVentiON also reLAtES TO a lIThographic appAratus for stEP-anD-scan iMaGinG Of a masK pattErN On a Number of areAs of A substratE, which APparatuS ComprisEs such A miRroR proJEcTiOn sYsTEm.
U.s. paT. No. 5,815,310 DEscRibes a miRrOr ProjeCtioN SYSTem fOr uSe in A step-And-scan lithogRapHic aPParAtus wIth whIch aN Ic mask PatterN is imAgEd on a number of arEas oF a semiconDucToR suBsTrate, USing EUv raDiaTion. EUV, Extreme ULtrAvIOLEt, Radiation is understOoD TO mEan radiaTion haVInG a WAvelengtH iN thE ranGE BetweEn seVErAl nm and sEveral TEnS oF nm. This RaDiatioN iS alSo rEferrED to aS soft X-Ray radiaTion. THE use of EUV radiaTIon provides thE GrEAT aDVantAge That extremeLy smALl deTailS, Of The ORder oF 0.1.mu.m oR lESs, CAn be imaged satisfactOrIly. In oTher wOrds, an imaging System in whICH eUV radiaTion IS uSEd has a very high ResolVing power wIThout the nA of tHe system Having to bE EXtremely LarGe, sO thAt aLSO tHe depth of focuS OF the SyStem stiLl hAs a reasOnaBly LarGe vAlUe. Since no Suitable MaTeRiAl Of wHich lENses can bE mAde Is AvaIlablE For EUV RadiaTion, A mIrROr pRojectiON sYSTem mUsT bE useD foR iMaginG the MAsk Pattern On the subsTraTE, insTeAd Of a hithErto conventioNaL lens projeCtIon System.
tHE lithogrAphic apparatuses currentLY used in The ProduCtioN of ICs are StePping aPpaRAtuses. in thesE appaRaTusES, A full FIElD ilLuMination is USEd, i.E. all aReAs of The mask Pattern are illuminaTEd sImultaneously And ThesE AReAs aRE sIMulTaNEouSLY imaged on an IC arEa of the subStRAtE. After a firST IC ArEa has beEn illumInateD, A step is Made to a suBsequent Ic aRea, i.E. THe sUbstrate hoLder is moVed in such A Way thAT tHe nexT IC Area wiLl Be pOsitiOned unDEr tHe masK patteRn, WhereaFter tHiS area is iLluminated, and so forth untIl all Ic areaS of The substrAte OF thE mask pattErn aRe illuminaTed. as iS knowN, it REmainS desIRaBle TO have iCs wITh an increASiNg nUMBeR of componenTS.
iT is AttemPteD To meet This Desire not only by reDUcing the dimensIons OF TheSe cOMponEnTs but also
. To display such an indic ator, a ne w set  of  co nt rolsign als must typic a llybe generated for the d ispla ys yste m .Somet imes, t h is c anre qu ire  a gr eat d eal  of ove rhead. The  in ve ntion relate s  t o a mirror  pr ojection sys tem  for u se  in a ste p-a nd-sc an lit h ograph ic projec ti o n appa r atus fo r im agin g a mask pattern, pr e sent in a mask , on a  s u bs t r ate  by  means ofabeamo f EUV r a di a t i on, which beam ha s a circula r  se gment- sh ape d  cross -sect io n .
T he inventio n al so relate s to a lithogr a phic ap paratu s f orstep - an d- sca ni mag i ng  of a m ask patt er non anumb e r o f ar eas  ofa sub strate, which  ap para t uscompr isessuch  a  mirr or pro jecti on  system.
U.S. P at.No. 5,815 ,31 0des cr ibesa  mirro r p roj ectionsystemf orus e i na step-and-scan li th o g ra phic app aratus wi th which an  I C m askp a ttern  isi ma ged on a  numbe r  o fareas o fa semi co ndu cto r sub s trat e, usi ng EUV r adiat i on. EUV, extre m e ultraviolet ,  r a d ia t ionisunderstoodto m e an r adia t io n h a vinga wav el e ng t h in the range betw ee n seve ral n m and several  tens of n m . This rad iati o ni s also referre d toas soft X- r ay radia tion.  The use  of EUV r a d iation p rov ide s t heg r ea t advantage t h a t ex tr emely s mal l detai ls,  of  th e o rd er of 0.1 .mu.m or  l es s,  c anbe im a ged sati sf act or ily . Ino ther w ords,  anim ag i ngsystemi nw h ichEU Vradi ati on  is u sedh asa veryhigh reso lvi n g po we rwithout  the NA of th esystem hav in g t o be e x t remely l arge, so that also thed epth of  fo cus o f th e systemsti ll has  ar easona bly la rge v al ue. S incen o  s uit ab le materia l ofwhich  l ense s can b e made is availabl e  fo r EUV radiati on,  a m i r ro r p r oj e cti on sys t e m must be usedfor imagin gt he  mask patt e rnon  the su bstrate , ins t ead ofa hithert o convent io nall e nsprojection  system. 
The lith o graph i cappar atu ses cu rr ent ly us ed int heprodu ctionof  ICs a re st ep ping app aratuses. In these appa ratuse s, aful l field i llu m ina tion is u sed,  i.e. allare asof th e m a sk pa tter n  a rei llumi nate d  simultan e ou sly a nd  these area s a resimul tan e ouslyimag ed on an IC areao f the substrat e. A f t era f i rstIC  area has been  il lu m i nated, a  s tep is made  to a su bs e quent  IC ar ea, i. e. thes u bs t rate h olde r i s moved i n s uc h  a wayth at the ne xt I Carea w ill be posi t i oned under the m ask p a t tern, whe reaft er  this a r ea i s illumina ted, and so  forth  unt il al l IC ar ea s of t hesu bstrate of the maskpatte rn areil lumi nat ed. As  isk n own,it r em ain s desirab l e  t o  h av e  IC s wi th an  i ncre asing num b er of co mpo n ents.
I tisa t tempte d  t o meet thisdes ire n o t  only by r e duci n gt he di mensio ns ofthese c o mpo ne nts but  al s o 
. To_display such_an indicator, a new_set of_control_signals must_typically_be generated for_the display system._Sometimes, this can require_a great deal_of_overhead. The invention relates to a mirror projection system for use in a step-and-scan_lithographic_projection apparatus_for_imaging_a mask pattern, present in_a mask, on a substrate_by means_of a beam of EUV radiation, which beam_has_a circular segment-shaped_cross-section.
The invention also relates to a lithographic apparatus for_step-and-scan imaging of a mask pattern_on a number_of_areas_of a substrate, which_apparatus comprises such a mirror projection_system.
U.S. Pat. No. 5,815,310 describes a_mirror projection system for use in a_step-and-scan lithographic apparatus with which an_IC mask pattern is imaged_on a_number of areas of a_semiconductor substrate, using_EUV radiation._EUV, extreme ultraviolet,_radiation is understood to mean radiation_having a wavelength_in the range between several nm_and_several tens of_nm._This_radiation is_also referred to_as_soft X-ray_radiation._The use of EUV radiation provides_the_great advantage that extremely small details, of_the order of 0.1.mu.m_or_less, can be imaged_satisfactorily. In other words, an_imaging system in which EUV radiation_is used_has a_very high resolving power without the NA of the system having_to be extremely large, so that_also the depth of_focus of_the_system still has_a_reasonably large_value. Since no suitable material of which_lenses can_be made is available for EUV_radiation, a mirror projection_system_must be used for imaging the_mask pattern on the substrate, instead_of a hitherto conventional lens_projection_system.
The_lithographic apparatuses currently used in_the production of ICs are stepping_apparatuses. In these_apparatuses, a full field illumination is used,_i.e._all areas of the mask pattern_are_illuminated simultaneously and these areas are_simultaneously_imaged_on an IC area of_the substrate. After a first IC_area has been illuminated, a step is made to_a subsequent IC_area, i.e. the substrate holder_is_moved_in such a way that the next IC area will_be positioned_under the mask_pattern, whereafter this area is illuminated, and so forth until_all IC areas of the substrate of_the mask pattern are illuminated. As is known, it remains desirable_to have ICs with an increasing number of_components.
It is attempted to meet this desire_not only by reducing_the_dimensions of these components but also