SMT-16EtchCD

1、©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaSemiconductorManufacturingTechnologyMichaelQuirk&JulianSerda©October2001byPrenticeHallChapter16Etch©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerda©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaObjectivesAfterstudyingthematerialinthischapter,youwillbeableto:1.Listanddiscusseightimportantetchparameters.2.Explaindryetch,includingitsadvantagesand。

2、howetchingactiontakesplace.3.Listanddescribetheequipmentsystemsforsevendryplasmaetchreactors.4.Explainthebenefitsofhigh-densityplasma(HDP)etchandthediscussthefourtypesofHDPreactors.5.Giveanapplicationexamplefordielectric,siliconandmetaldryetch.6.Discusswetetchanditsapplications.7.Explainhowphotoresistisremoved.8.Discussetchinspectionandimportantqualitymeasures.©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaApplicationsforWaferEtchinCMOSTechnologyPhotoresistmas。

3、kFilmtobeetched(a)Photoresist-patternedsubstrate(b)SubstrateafteretchPhotoresistmaskProtectedfilmFigure16.1©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaProcessFlowinaWaferFabImplantDiffusionTest/SortEtchPolishPhotoCompletedwaferUnpatternedwaferWaferstartThinFilmsWaferfabrication(front-end)UsedwithpermissionfromAdvancedMicroDevicesFigure16.2©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchProcessCategoriesofEtchProcesses•。

4、WetEtch•DryEtch•ThreeMajorMaterialstobeEtched–Silicon–Dielectric–Metal•PatternedEtchVersusUnpatternedEtch©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchParameters•Etchrate•Etchprofile•Etchbias•Selectivity•Uniformity•Residues•Polymerformation•Plasma-induceddamage•Particlecontaminationanddefects©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchRateTStartofetchEndofetcht=elapsedtimeduringetchT=changeinthicknessFigure16.3。

5、©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaWetChemicalIsotropicEtchIsotropicetch-etchesinalldirectionsatthesamerateSubstrateFilmResistFigure16.4©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaAnisotropicEtchwithVerticalEtchProfileAnisotropicetch-etchesinonlyonedirectionResistSubstrateFilmFigure16.5©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaSidewallProfilesforWetEtchVersusDryEtchTabl。

6、e16.1TypeofEtchSidewallProfileDiagramWetEtchIsotropicIsotropic(dependingonequipment¶meters)Anisotropic(dependingonequipment¶meters)Anisotropic–TaperDryEtchSiliconTrench©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchBias(b)BiasSubstrateResistFilm(a)BiasResistFilmSubstrateWbWaFigure16.6©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchingUndercutandSlopeUndercutSubstrateResistFilmOveretchFigure16.7©2001byPrenticeH。

7、allSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchSelectivityS=EfErEfNitrideOxideErFigure16.8©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaEtchUniformityMeasureetchrateat5to9locationsoneachwafer,thencalculateetchuniformityforeachwaferandcomparewafer-to-wafer.Randomlyselect3to5wafersinalotFigure16.9©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaPolymerSidewallPassivationforIncreasedAnisotropyPlasmaionsRe。

8、sistOxidePolymerformationSiliconFigure16.10©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaDryEtch•AdvantagesofDryEtchoverWetEtch•EtchingAction•PotentialDistribution©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaAdvantagesofDryEtchoverWetEtch1.Etchprofileisanisotropicwithexcellentcontrolofsidewallprofiles.2.GoodCDcontrol.3.Minimalresistliftingoradhesionproblems.4.Goodetchuniformitywithinwafer,wafer-to-waferandlot-to-lot.5.Low。

9、erchemicalcostsforusageanddisposal.Table16.2©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaPlasmaEtchProcessofaSiliconWafer8)By-productremoval1)EtchantgasesenterchamberSubstrateEtchprocesschamber2)Dissociationofreactantsbyelectricfields5)Adsorptionofreactiveionsonsurface4)Reactive+ionsbombardsurface6)SurfacereactionsofradicalsandsurfacefilmExhaustGasdeliveryRFgeneratorBy-products3)Recombinationofelectronswithatomscreatesplasma7)Desorptionofby-productsCathodeAn。

10、odeElectricfieldllAnisotropicetchIsotropicetchFigure16.11©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaChemicalandPhysicalDryEtchMechanismsReactive+ionsbombardsurfaceSurfacereactionsofradicals+surfacefilmDesorptionofby-productsAnisotropicetchIsotropicetchSputteredsurfacematerialChemicalEtchingPhysicalEtchingFigure16.12©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaChemicalVersusPhysicalDryPlasmaEtchingEtchParameterPhysicalEt。