IC工艺技术2-_光刻.ppt

单击此处编辑母版标题样式,*,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,IC,工艺技术系列讲座,第二讲,PHOTOLITHOGRAPHY,光刻,讲座提要,1.General,2.Facility(,动力环境,),3.Mask(,掩膜版,),4.Process step highlight(,光刻工艺概述,),5.BCD,正胶工艺,6.History and,未来的光刻工艺,1.General,MASKING Process(,光刻工艺,),Photolithography,(,光学光,刻,),-Transfer a temporary pattern(resist),Defect control,Critical dimension control,Alignment accuracy,Cross section profile,Etch,(,腐蚀,),-Transfer a permanent pattern(Oxide,Nitride,Metal),2.0Facility requirement,Temperature (,温度,),70,o,F,Humidity(,湿度,),45%,Positive pressure(,正压,),0.02in/H,2,O,Particle control(,微粒,),Class 100,Vibration(,震动,),Yellow light environment(,黄光区,),DI water(,去离子水,)17mhom,Compress air and Nitrogen(,加压空气,氮气,),In house vacuum(,真空管道,),3.0Mask(,掩膜版,),Design,PG tape,Mask making,Plate-quartz,LE glass,Soda line glass,Coating-Chrome,Ion oxide,Emulsion,Equipment-E-beam,Pattern generator,Mask storage,-,Anti static Box,Pellicle,Pellicle protection,4.0,光刻工艺概述,Prebake and HMDS,(,前烘,),Resist coating,(,涂胶,),EBR(,去胶边,),soft bake,3.Exposure,(,曝光,),Alignment(,校正,),4.Develop,(,显影,),Post e-bake,Hard bake,backside rinse,5.Develop inspection,(,显检,),4.1Prebake and HMDS treatment,Purpose of Pre-bake and HMDS treatment is to improve the resist adhesion on oxide wafer.HMDS is adhesion promoter especially designed for positive resist.,HMDS(Hexamethyldisilane)can be applied on the wafers by,1.Vapor in a bucket,2.vapor in a vacuum box,3.Directly dispense on wafer,4.YES system-in a hot vacuum system,5.Vapor in a hot plate(with exhaust),Too much HMDS will cause poor spin,vice versa will cause resist lifting,4.2Resist Coating(,涂胶,),Resist coating specification(,指标）,Thickness,（厚度）,0.7u 2.0u (3.0,以上,for Pad layer),Uniformity,（均匀度）,+,50A,+,200A,Size of EBR,（去胶边尺寸）,Particle,（颗粒）,20 per wafer,Backside contamination(,背后污染）,三个主要因数影响涂胶的结果,ResistProduct(,产品）,Viscosity,（粘度）,SpinnerDispense method,（涂胶方法）,Spinner speed(RPM),（转速）,Exhaust,（排气）,Soft bake temperature,（烘温）,FacilityTemperature,（室温）,Humility,（湿度）,4.2.1Coater(,涂胶机）,Equipment module and special feature,Pre-bake and HMDS-Hot/Cold plate,Resist dispense-Resist pump,RPM accuracy-Motor,EBR-Top/bottom,Hot plate-soft bake temperature accuracy,Exhaust,Waste collection,Temperature/Humidity control hood,Transfer system-Particle and reliability,Process step and process program-Flexible,SVG 8800,升降机,涂胶,HMDS,热板,冷板,升降机,升降机,升降机,涂胶,热板,热板,升降机,升降机,升降机,升降机,涂胶,热板,冷板,HMDS,冷板,冷板,冷板,涂胶,热板,热板,升降机,升降机,显影,热板,热板,热板,冷板,4.2.2 Coater(,涂胶机）,combination,4.2.3 Coater(,涂胶机）,Resist dispense methods,Static,Dynamic,Radial,Reverse radial,Resist pump,(Volume control-2cc/wafer and dripping),Barrel pump-Tritek,Diaphragm pump-Millipore,N2 pressure control pump-IDL,Step motor control pump-Cybot,size of dispense head,4.2.4 Coater(,涂胶机）,rpm,(,转速）,and acceleration,（加速）,Maximum speed-Up to 10000 rpm,Stability-day to day,Acceleration-controllable number of steps,Reliability-time to replacement,EBR(Edge bead removal),（清边）,Method-Top EBR or Bottom EBR or Top and bottom EBR,Problem-Dripping,Chemical-Acetone,EGMEA,PGMEA,ETHLY-LACTATE,Resist Type,Negative resist,Positive resist,G-line,i line,reverse image,TAC-top anti-reflective coating,BARLI-bottom anti-reflective coating,Chemical amplification resist,X ray resist,4.3.1 Exposure(,曝光,),Transfer a pattern from the mask(reticle)to resist,Goal,1.Critical Dimension control(CD),条宽,2.Alignment,校准,-Mis-alignment,run in/out,3.Pattern distortion,图样变形,-Astigmatism,4.Cross section profile,侧面形貌,-side wall angle,5.Defect free,无缺陷,Equipment/mask/resist selection,1.Resolution,分辨率,-Expose character,Light source(wavelength),N/A,2.Auto-alignment skill,自动校准技术,-Light field,dark field,laser,3.Mask,掩膜版,-e-beam master,sub-master,spot size,quartz plate,defect density,CD requirement,4.Resist selection,胶选择,4.3.2Exposure(,曝光,),Aligner Technology,1.Contact print(,接触）,Soft contact,hard contact,proximity,2.Scanner(,扫描）,3.Stepper(,重复）,1X,2X,4X,5X,10X,4.Step Scan(,重复扫描,),4X-reticle move,wafer move,reticle/wafer move,5.X ray(X,光）,1:1,6.E-beam(,电子束）,-Direct write,4.3.3Exposure(,曝光,),Contact print(,接触）,1.Most of use for negative resist process-for 5u process and can be push to 3u.,2.Positive resist can print smaller than 3u,and deepUV can push to 1u,but very high defect,3.Equipment:,-Canon PLA 501,-Cobilt,-Kasper,-K&S,Contact print-Canon 501,4.3.4Exposure(,曝光,),Scanner(,扫描）,1.Most of use for G line Positive resist process-for 3u process and can be push to 2u.,2.Negative resist can print smaller than 4u,3.Equipment:,-Canon MPA 500,600,-Perkin Elmer 100,200,300,600,700,900,PE 240 Scanner,Canon 600 Scanner,4.3.5Exposure(,曝光,),Stepper(,重复）,1.G line positive resist-for 0.8u process,2.i line positive resist-0.5u process,3.i line resist plus phase-shift mask-can be pushed to 0.35,4.deepUV resist process,-0.35u and below,5.Equipment:,-,Ultratech,-Canon,-Nikon,-ASML,4.3.6Exposure(,曝光,)6,ASML Stepper list,ModelWavelength Resolution,ASML 2500 g0.8,ASML 5000,ASML 5500 20,22,25,60,60B,80,80Bi0.55,ASML 5500 100,100C,100D,150i0.45,ASML 5000 200,200B,250,250B UV0.35,ASML 5500 300,300B,C,D,TFH UV0.25,ASML 5500-900 Step-Scan,UV,4.4.1Develop(,显影）,Develop process,1.Post expose bake,2.Resist Develop,3.DI water rinse,4.Hard Bake,Develop equipment,1.Batch develop,2.Track develop,Develop chemical,1.,KOH,2.Metal free(TMAH)-Tetramethylamoniahydroxide,3.Wetting agent-with/without,4.Concentration-2.38%TMAH,Track develop method,1.,Spray,2.Steam,3.Signal-Paddle,4.Double-Paddle,4.4.2 Develop(,显影）,Develop Track,1.Temperature control water jacket for Develop line,2.Develop pump/develop pressure canister,3.Exhaust,4.Hot plate temperature control,5.Pre-wet-process program,4.4.3Develop(,显影）,CD control in,developing,1.Post bake process,2.Develop Time,3.Concentration of developer chemical(Higher fast),4.Developer temperature (lower faster 1,o,C/0.1u),5.Develop recipe-pre-wet,paddle,rotation,6.Age of the develop chemical,7.Rinse-DI water pressure,8.Hard bake temperature,4.5.1Develop Inspection,Tool for inspection,1.Microscope,Manually loading,Automatic loading,2.UV lamp,Manually loading,Automatic loading,3.CD measurement equipment,Manually measuring system-Vicker,Automatic measuring system-Nanoline,CD SEM,4.5.2Develop Inspection,Inspection items,1.Layer name,2.Alignment,3.Run in/out,4.Pattern distortion,5.Pattern integrity,6.Defects,lifting,particle,discoloration,scumming,bridging,excess resist,scratch,7.CD(critical dimension),Nanoline-for CD measurement,Hitachi 8860-CD SEM,Leitz Microscope inspect station,Autoload UV inspection system,5.0 BCD,正胶工艺,Equipment SSI,SVG8800,SVG 90,Process steppre-bake/HMDS/cold plate,spin(5000rpm)-dynamic dispense,-top(bottom)side EBR(2mm),soft bake(100,o,C)/cold/palte,Resist/specShipley 6112(1.2u),1818(1.8u 1st metal),6818(2.4u 2nd metal),6118(2.9u Pad),6124(3.6u-4.5u ST),Everlight 533(1.2),Uniformity-,+,300A,Resist coating,升降机,冷板,HMDS,涂胶,热板,冷板,升降机,SVG 90,SVG 8800,5.1.1Positive Resist(,正胶）,Component(,成分）,Resin,（,树脂）,Diazonaphthoquinone(DNQ)/novolak,Photo-sensitizer,（感光剂）,Solvent,（溶剂）,Dye,（染料,）,Manufacturing(,制造商）,Kodak Hunt Ash chemical (USA),TOK(Japan),JSR(Japan),Shipley(USA),AZ(USA,Germany),Sumitomo(Japan),Everlight(Taiwan),5.1.2Positive Resist(,正胶）,Product Name and feature(,产品称与特性）,以,everlight,(,永光）正胶为例,Product SeriesEPG 510 Series,Expose wavelengthG-Line(435nm),Thickness,Name 2000rpm 5000rpm,Viscosity,（粘度）,EPG 510-12 cp1.25u0.80u,EPG 512-21.5 cp2.00u1.25u,EPG 516-50 cp3.25u2.00u,EPG 518-105 cp4.50u2.75u,EPG 519-460 cp9.00u5.5u,Resolution(,分辨率）,0.8u (0.55u-the smallest),Depth of Focus(,聚焦深度）,+,1.4u(1.0u line/space),Sensitivity(,感光度）,Eth=60 mj/cm2,Eop,=90 mj/cm2,5.1.4Positive Resist(,正胶）,Select a positive resist,1.Resolution,（分辨率）,2.Resist thickness-Spin curve,（厚度）,3.Photo speed,(,曝光速度,),4.Expose latitude,(,曝光宽容度,),5.Adhesion,（粘附性）,6.Reflective notch,（反射缺口）,6.Metallic content,（金属含量）,7.Thermal stability,（热稳定性）,8.Plasma resistance,（抗腐蚀能力）,9.How easy to be removed,（清除能力）,10.Price,（價格）,5.2Expose,Equipment,Ultratech,stepper 1100 (6”),Ultratech stepper 1500 (6”),Canon 600 (6”),Perkin Elmer 240 (4”),Positive Resist reaction during expose,Positive Resist reaction during expose,5.2.1Ultratech Stepper,Ultratech stepper,G-line,N/A-0.24 and 0.31,1:1 print ratio,3 X 5 inch reticle-3,4,5,7 field,4u depth of focus,Blind step can be push to 5u(no spec),Center of array,+,50u,Dark field alignment,Site by Site alignment,Alignment target,*oat-4mm X 4mm,*K/T-200u X 200u,Ultratech Stepper 1100,Ultratech Stepper 1500/1700,5.2.2,Ultratch,stepper specification,UTS-Reticle and Job file,Guide,Fiducials,UTS-primary lens,UTS AlignmentOptic,Ulratech,stepper site by site alignment,UT alignment procedure,Load job file into computer,Load reticle,Start,iducials alignment-Guide,rotation(1500),OAT alignment,OAT size=4mmX4mm,Fast and slow scan 1000u,Side by side alignment,Key and target size 200uX200u,shot scan 20u,long scan 100u(80u),Auto-focus,Goble or local,Failure alignment,Skip,Expose,Zmode,5.3 Perkin Elmer aligner,Micalign PE 100,Micalign PE 200,220,240,Micalign PE 300,340,340HT,Micalign PE 500,Micalign PE 600,Micalign PE 700,Micalign PE 900,Micscan 100,Micscan 200,Micscan 300,Micscan 400,PE 240,Specification,PE 240,PE 240,PM,Center of curvature,Parallelism,Light intensity,Focus,Distortion,Mask/wafer centering,View optic,HPC rebuild,Cooling air flow rate,Vibration from HPC,Facility,Vibration from environment,Temperature control hood,Process,Reference wafer,Aperture selection,Resist build up on XYO pins,Roof mirror cleaning,Mask heat up during expose,PE-Focus wedge mask,PE-distortion,PE-Projection optic,PE Mercury lamp,PE-Adjustable slit,PE alignment procedure,Set scan,Load mask,Load wafer,Switch to mask,Use microscope and carriage movement to find the alignment mark on mask(Test die),Move mask only to align the wafer,Switch to wafer,Move wafer align to mask,5.4.1Resist develop,Equipment SSI,SVG8800,SVG 90,Process steppose-e bake/cold plate,develop -double paddle,-DI water rinse,-back N,2,/rinse,hard bake(110-130,o,C)/cold/palte,DeveloperTMAH 2.35%,升降机,冷板,热板,冷板,升降机,热板,显影,SVG 8800,SVG 90,5.4.2 Resist develop,Equipment Develop sink,Equipment set upTemperature,N2 blanket,Filter size,Filter change,DeveloperTMAH 2.38%,Develop change,Process step,batch develop-immerse (1&15”),QDR DI water rinse(8 cycles),hard bake(110-130,o,C)/cold/palte,6.History and,未来的光刻工艺,Will imprint technology replace photolithography?,In 1798,image was transferred by stone plate,1940,Bell Lab used resist developed by Eastman Kodak,1960,San Francisco bay area becomes the silicon valley-AT&T,Raytheon,Fairchild,Negative resist contact print process wildly was used.,End of 1970-early of 1980,positive resist Projection print(Perkin Elmer Micalign)started to be used in production.Bay area became cloudy-National,Intel and AMD.Outside bay area had Motolora,TI,IBM.,From 1970 to early 2000,the technology of semiconductor is developed very fast.The smallest feature size from 10u reduced to 0.09u.0.25u and 0.35u products were running mass production every where-USA,Europe,Japan,Taiwan,Korea i-line,and deepUV-5X stepper and step-scan(4X)aligner became the major tools.,Now,0.09u technology become mature.0.065u,0.045u and 0.035u technology are being developed.Immersion lithography and imprint technology will be used to print these nano feature.,Imprint technology claims that it is able to print 0.01u(10nm)-It may be the future masking.,6.1History,Lithography,as used in the manufacture of the integrated circuit,is the process of transferring geometric shapes on a mask to the surface of a silicon wafer.These shapes make up the parts of the circuit,such as gate electrodes,contact windows,metal interconnections,and so on.Although most lithography techniques used today were developed in the past 40 years,the process was actually invented in 1798;in this first process,the pattern,or image,was transferred from a stone plate(the word litho comes from).,The first practical two dimensional device patterning on a silicon wafer was actually carried out in the late 1940s at the Bell Lab.At that time,polyvinylcinnamate,developed by Eastman Kodak,was used as a resist.However,device yields were low because of the poor adhesion of the polyvinylcinnamate to the silicon and oxide surface.The Kodak chemists then turned to a synthetic rubber based material-a partially cyclized isoprene and added a UV active sensitizer-a bis-aryl-azide into it to crosslink the rubber matrix and created a new class of photoresist material.Since the unexposed area of the new material was the only part of the polymer matrix that will dissolve in an organic solvent and yielding a negative image of the mask plate,therefore,the new material was then referred as the negative resist.,The cyclized rubber/bisazide resist was widely used in the contact printing age.However,the contact mode of printing created severe wear of the mask plate and the defect density of the photomask and the wafer was very high.The industry therefore decided to switch to contactless projection printing in 1972 for producing the 16k DRAM.,Projection printing,however,was carried out in the Fraunhoffer or the so called far field diffraction region and the aerial image was much poorer than the contact or proximity method of printing.In order to preserve the same quality of image structure,the contrast of the image material must be increased.,Lithographic lore has it that the diazonaphthoquinone/novolak resist(the term novolak is derived from the Swedish word lak,meaning lacquer or resin and prefixed by the Latin word novo,meaning new)made their way from the blue print paper industry to the microelectronic through family ties:at that times,the offices of Azoplate,the American outlet for Kalle printing plate,was located at Murray Hill,NJ,just across the street from the famous Bell Labs.The father of a technician at Azoplate worked as a technician at Bell Labs.Apparently the father had complained one day about the poor resolution quality of the solvent developed resist system used at the Bell Labs and the son had boasted the properties of the Azoplate DNQ/novolak material;anyway,one day the father took a bottle of the material with him to the Bell Labs,and the age of the DNQ/novolak resist began.,The new material was marketed by Azoplate under the trade name of AZ photoresist.It was always referred as the positive resist for a positive tone of image would be reproduced by the new material.The use of DNQ/novolak system increased rapidly after the introduction of the projection lithography.By 1980s,the DNQ resist had completely supplanted the old negative resist as the workhorse of the semiconductor industry in the high-end applications.,The DNQ/novolak resist has held sway for 6 device generations,from the introduction of the 16K DRAM to the large scale production of the 64M DRAM in 1994 to 1995.The success of such material was the indicative of it supreme performance and potential.,Today,it appears that it is not really the resolution which defines the limit of the DNQ/novolak resist application,but rather the loss in the de