微專業(yè)---半導(dǎo)體制造技術(shù)課程：半導(dǎo)體工程專業(yè)英語ContentsSemiconductorProperties半導(dǎo)體特性01SemiconductorMaterials半導(dǎo)體材料02SemiconductorDeviceandHowTheyareUsed半導(dǎo)體器件及其使用03ProcessTechnology工藝技術(shù)04FabricationProcesses制造工藝05SemiconductorMaterialsandProcessCharacterization半導(dǎo)體材料與工藝表征06FabricationProcesses5.1PatternDefinitionSchemes5.2ProcessingStepsinTop-DownSequence5.3SurfaceProcessing5.4AdditiveProcesses5.5Lithography5.6SubtractiveProcesses5.7SelectiveDoping5.8ProcessingofContactsandInterconnects5.9AssemblyandPackaging051Introduction

Lithographyisessentiallyaprintingtechniquewhichinsemiconductordevice

manufacturingisofkeyimportanceasitdefinesthegeometryofsemiconductordevices,andthus,determinesbasiccharacteristicsandperformance

ofeachofthem.Inthecaseoflithographicpatterntransfertheprocessis

implementedusingshort-wavelengthUVlightasaprintingenergycarrier,

theprocessisknownasphotolithography(alsoreferredtoasopticallithography).Aswillbediscussedlater,varioustypesofphotolithographyare

distinguishedbasedonthewavelengthoftheUVlightused.Inanalternativeapproach,afocusedelectronbeamisemployedasaprintingmedium

andthetechniqueisknownase-beamlithography./??mpl?ment?d/實施5.5Lithography/?l?θ??ɡr?f?k/光刻5FabricationProcesses2

Asstatedearlier,theprocedureusedtotransferthepatternontothesurface

ofthesemiconductorwafer

isreferredtoas“l(fā)ithography”.The

implementationofthelithographicprocessrequires:(i)energyintheformofasshortwavelengthaspossibleUVlight(photolithography),orelectron

beam(e-beamlithography)impingingontheprocessedsubstratetoinitiate

patterndefiningreactionsonitssurface,(ii)meanstolocalizetheimpactof

energyonthesurface,and(iii)mediumrespondingtothisimpactsothat

theeffectofthedeliveredenergycanberegistered./?red??st?rd/記錄5.5Lithography/?lo?k?la?z/局部的/??mpl?men?te??(?)n/實施5FabricationProcesses5.5.1

ImplementationoflithographicprocessesText35.5Lithography5FabricationProcesses5.5.1

Implementationoflithographicprocesses(a)Maskbasedpatterningand(b)directwritepatterning.4Exposurewavelengthandresolution.First,usingaphysicalobjectknownasamaskwhichisconfiguredsuchthatitallowsUVlighttopassthroughandtoexposephotoresistonlyintheareasnotcoveredbytheopaquetoUVmaterialformingonthesurfaceofthemaskapatterntobetransferred.Thenumberofmasksusedatvariousstagesofthedevicemanufacturingsequencedependsonthecomplexityoftheprocesseddeviceandmayvaryfromjustafewinthecaseofthesimplediscretedevicestoovertwentyinthecaseofcomplexintegratedcircuits./o??pe?k/不透明的5.5Lithography5FabricationProcesses5.5.1

Implementationoflithographicprocesses/k?m?pleks?ti/復(fù)雜性/d??skri?t/分立的5Exposurewavelengthandresolution.Intheprocesseswheretheveryhighprecisionofthepatterntransferprocessisrequired,andthetimeneededtodelineatethepatterninthelayeroftheresistisnotofmajorconcern,thedesiredpatterncanbedirectlywrittenintheresistusinghighlyfocusedelectronbeamscannedoverthesurfaceofthesubstratewafer.Thisexposuremodeisreferredtoasadirectwritelithography./d??l?nie?t/描繪5.5Lithography5FabricationProcesses5.5.1

Implementationoflithographicprocesses6Exposurewavelengthandresolution.Thetermresolutionisconcerned

withtheaccuracyofwhichpatternfromthemaskisbeingtransferredtothe

layerofphotoresist.Whensmallergeometricalfeaturesneedtobecreated,

higherresolutionpatterntransferprocessisrequired.Alimitingfactoris

theeffectofdiffractionattheedgesofthemaskofwhichadverseeffecton

theresolutionofthepatterntransferprocessisillustratedin.Theextentofdiffraction,andthusresolutionofthepatterntransfer,dependsonthewavelengthoflightλpassingthroughthemask

andislesspronouncedasthewavelengthisgettingshorter.Consequently,

asshortastechnicallyviablewavelengthsoflightareusedinpatterndefinitionprocessesinsemiconductordevicemanufacturinginthecaseswhere

thegeometriesinthelownanometerrangeneedtobecreatedonthewafer

surface./d??fr?k?n/衍射5.5Lithography5FabricationProcesses5.5.1

Implementationoflithographicprocesses/pr??na?nst/明顯的/?d?v??rs/不利的75.5Lithography5FabricationProcesses5.5.1

ImplementationoflithographicprocessesTheeffectofdiffractiondefiningresolutionofthe

photolithographicprocessissmallerasthewavelengthλofthelightusedforexposureisshorter.8

Respondingtotheneedtouseshort-wavelength,highintensitylightin

patterndefinitionlithographicprocesses,theUVlightrepresentingshort

wavelengthendoftheelectromagneticspectrumisusedasenergycarrying

mediuminpatternexposureapplicationsinsemiconductordevicefabrication.Asmentionedearlier,thelithographyusingUVlightfortheresist

exposureiscommonlyknownasphotolithography,oropticallithography.

WithintheUVspectrumthereareselectedcharacteristiclines(wavelengths)

identifiedwhichfeatureparticularlyhighintensityandwhich,dependingon

theneedsdrivenbytherequiredresolutionofthepatterntransferprocess,

areusedinphotolithography.5.5Lithography/?spektr?m/頻譜5FabricationProcesses5.5.2

ImplementationoflithographicprocessesText95.5Lithography5FabricationProcesses5.5.2

ImplementationoflithographicprocessesCharacteristiclinesinUVspectrumusedinphotolithography.10DeepUV(DUV)photolithographyisemployedwhenthepatterningis

concernedwithgeometricalfeaturesinthenano-scalerangefrom10nmto

250nm.

Forallpracticalpurposes193nmwavelengthis

arecognizedstandardbearerintheareaofadvancedphotolithography./?ber?r/載體5.5Lithography5FabricationProcesses5.5.2

Implementationoflithographicprocesses11ExtremeUV(EUV)photolithography.Patterningofgeometricalfeaturesat7nmandbelow,inprinciplerequiresusingUVwavelengthsfromthe

extremeUVrangewithinwhich13.5nmwavelength

is

commonly

used.TechnologyofEUVphotolithographyisdrasticallymorecomplexand

costlythanDUVphotolithography,andthus,isusedinthesituationsrequiringdefinitionofsinglenanometer-scalegeometricalfeaturesinthemanufactureofleading-edgedigitalIC.5.5Lithography5FabricationProcesses5.5.2

Implementationoflithographicprocesses12Photomask.ThemasksusedinUVandDUVphotolithographyarecalled

photomasksandaretransmissive.Bydefinitionaphotomaskconsistsoftwoparts.ThefirstoneistransparenttoanygivenUVwavelengthsusedandcommonlyreferredtoasablank.ThepartofthemaskthatneedstoblockoffUVlight,inotherwordsopaqueportionofthemask,isintheformofthin-filmofopticallyverydensematerialsuchasmostcommonly,chrome(Cr)./kro?m/鉻5.5Lithography5FabricationProcesses5.5.2

Implementationoflithographicprocesses/o??pe?k/不透明的/dens/密度高/tr?nz?m?s?v/透射的135.5Lithography5FabricationProcesses5.5.2

ImplementationoflithographicprocessesTransmissivephotomask./tr?nz?m?s?v/透射的/o??pe?k/不透明的14Photoresist.

Thematerialdepositedonthesurfaceofthewaferforthe

purposeofregisteringthelocalimpactoftheenergycarriedbyUVlight

iscalledaresist.Intermsofchemicalcomposition,theresists

areorganiccompoundsformulatedsuchthattheyrespondwithhighsensitivitytothespecificalwavelengthofUVlightwhichmeansthatdifferently

formulatedphotoresistsareusedintheconventionalphotolithography,and

DUVlithography,forinstance.Stilldifferentresistsareusedine-beam

lithographydiscussedlater./?f??rmjule?t/制訂5.5Lithography5FabricationProcesses5.5.2

Implementationoflithographicprocesses15

Therearethreedifferentwaysexposureofphotoresistusingtransmissive

maskscanbeimplemented.Thetechniquesinvolved,referredtoascontact

printing,proximityprinting,andprojectionprinting.5.5Lithography5FabricationProcesses5.5.3

ExposuretechniquesandtoolsinphotolithographyText(a)Contactprinting,(b)proximityprinting,and(c)projectionprinting./pr??d?ek?(?)n/投影/?ret?kl/掩模板16

Projectionprintingisthemostcommonphotolithographytechniquein

theindustrialmanufacturingprocesses.Itrepresentsadeparturefromthe

principlesofthecontactandproximityprintinginthatthepatternonthe

maskisprojectedonthesurfaceofthewafernotdirectly,butthrough

thecomplexlenssystempositionedbetweenthemaskandthewafer.Withthisconfiguration,theimagecreatedbyUVlightpassingthroughthemask(reticle)canbemanipulatedtowardimproved

accuracy(resolution)ofthepatterntransferusingadequatelydesignedlens

systempositionedwithinashortdistancefromthewafersurface.5.5