Samsung AMOLED (三星的AM- OLED制程介绍)

AMOLEDdrivenbySolution-ProcessedOxideSemiconductorTFTsMyung-KwanRyuDisplayLaboratorySamsungAdvancedInstituteofTechnology(SAIT)PrintedElectronicsAsia2009MK-RYU2I.Introduction&BackgroundII.InZnO(IZO)solutionandspin-coatedIZOfilmsIII.IZO-TFTsandAMOLEDIV.Summary&ConclusionContentsPrintedElectronicsAsia2009MK-RYU3Binary,ternary,quaternary,…ZnO,In2O3,Ga2O3,SnO2,ZnO-derivatives:InZnO(IZO),GaInZnO(GIZO),ZnSnO(ZTO),InAlO(AIO),InZnSnO(IZTO),AlSnZnO(ATZO),AlSnZnInO(ATZIO),ZnZrO(ZZO),ZnMgO(ZMO),MgInZnO(MIZO),etcBackground:OxidesemiconductorsMainelementsSub-elementsPrintedElectronicsAsia2009MK-RYU4Background:ZincOxideTFT(Highperformance)HighmobilityLarge&highresolutiondisplay1.E-141.E-131.E-121.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-04-20-1001020VGS(V)IDS(A)a-SiTFTμ=0.6cm2/Vsa-GaInZnOTFTμ2cm2/VsGIZO:Sputtera-Si:PECVDPixelchargingtimeFHD(1920x1080)60HzRC-delayGatepulseUD(4096x2160)120Hz15.4μs3.8μsHighmobilityofpixelTFTisrequired,becausethepixel-chargingtimeissignificantlydecreasedbytheshortenedgatepulseandtheRC-delay.Kwon(IMID2007)PrintedElectronicsAsia2009MK-RYU5Background:ZincOxide(Transparentmaterial)TransparencyWidebandgapTransparentDisplay(TD)ConductionbandValencebandEg~3.4eVModulationofelectricalproperties-Conductor-Semiconductor-InsulatorTransparentTFT-Electrode-Channel-Dielectric0102030405060708090100350450550650750Wavelength[nm]Transmittance[%]Transmittance(IZO)PrintedElectronicsAsia2009MK-RYU6Background:ZincOxide(Solution-processibility)%intotalcapitalcostsforTFT-LCDline14%14%8%22%42%VacuumsystemPhotolithoEtcTFT-Array(Frontend)Back-endFacilitiesVac.&PhotolithoprocessSolution-processSubstrateFilmAnnealingCoating,PrintingPrecursorsolution(Printableink)+PrintableZnOinkSpin-coating(SC),Ink-jetprinting(IJP)Lowcost&simpleprocessLimitationtocost-downinlarge-size(Gen10)fabs.duetohugeinitialinvestmentforprocessequipments(Deposition,etching,photolithography)PrintedElectronicsAsia2009MK-RYU7Solution-processedoxideTFT:Trend2003‘04‘05‘06‘07TransparentTFT(ZnO)Multi-component(ZnZrO)InkJetPrinted(IJP)IZO,ZTO‘08OregonStateUniv.NCTUniv.IZOOregonStateUniv.Multi-component(GIZO)YonseiUniv.AMLCD(ZnZrO)4in,QVGAμ=0.0042cm2/VsTTLAHighμIJP-ZnOOregonStateUniv.ZnOAl(S/D)150~300oCETRIRTnano-ZnONano-ZnOCavendishLab.‘09IJPGIZOYonseiUniv.ZnO,multi-componentZnO(precursor-type,nano-P/Ttype)Spin-coating,ink-jetprinting.FilmformationTemp.=150~600oC(precursor),RT~200oC(nano-P/T)T-TFT,AMLCD(PerformancesoffullprocessintegratedTFTswasnotgoodenough…),AMOLED(?)PrintedElectronicsAsia2009MK-RYU8HighperformanceTFT-backplaneChannel:Spin-coatedInZnO(IZO)-Ternarysystem:relativelysimple-Zn-andIn-precursorsolution-Amorphous:goodforuniformity-PerformanceenhancementbyIn:OptimizationofIn/ZnratioAMOLEDdrivenbysolution-processedoxideTFTsOurworkPrintedElectronicsAsia2009MK-RYU9IZO-SolutionPrecursor:Zn-R’,In-R”(nitrate,acetate,acetylacetonate,halide,hydroxide,etc)Metalalkoxides,acetyleacetonate,acetate:-(OCH3)x,-(OH2CH3)x,-(CH3COO)x,-(CH3COCHCOCH3)x,Metalsalts(nitrate,chloride,oxychloride,hydroxide..):-(NO3)x,-Clx,-(OH)x,…Ourwork:Zn(CH3COO)3-2H2O,In(NO3)3orIn(CH3COCHCOCH3)3Solvent:2methoxyethanol(2ME),NH3(aq),ethanol,wateretcStabilizer:acid,base,water,..ex)MEA,DEA,Aceticacid,MOHx,Acetol,Glycine,…MEAAceticacidDEAAcetolGlycineGelation,precipitationPrintedElectronicsAsia2009MK-RYU10Spin-CoatedIZOfilms:ProcessDroppingglasscoaterSpinning2step-annealing•Softbake:250~300oC•Hardbake:350~450oCHotplate•rpm=500~3000PrintedElectronicsAsia2009MK-RYU11Spin-CoatedIZOfilms:Composition0.00.51.01.52.02.53.03.50.00.51.01.52.02.53.03.5SolutionFilmZn/InZn/Inofsolution&filmIn/Zn=3forTFT-channelPrintedElectronicsAsia2009MK-RYU12Spin-CoatedIZOfilms:DepthprofileAESdepthprofile020406080100050100150Sputtertime[sec]Intensity[a.u.]InOZnSiCSiwaferIZO(In/Zn=3)SiwaferIZO(In/Zn=3)PrintedElectronicsAsia2009MK-RYU13HR-TEMSpin-CoatedIZOfilms:SolidStatePhase5nm5nm5nmamorphousXRDPrintedElectronicsAsia2009MK-RYU14Spin-CoatedIZO-TFTs:Back-channeletch(BCE)structureSpin-coatedIZOSputter-dep.MoGlassPECVDSiNxBottomGate(BG),source/draintop-contact(TC)S/Dpatterning:DryetchingPassivation(PVX):PECVD-SiO2SiO2MoMo2000ASiNxGlassAmorphousIZOSiO2MoMo2000A2000ASiNxGlassAmorphousIZOPassivation(PECVDSiO2)PrintedElectronicsAsia2009MK-RYU15TFTcharacteristicateachprocessstep,In:Zn=3:11.E-131.E-121.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-04-40-30-20-10010203040Gatevoltage[V]Draincurrent[A]After250C-annealing1.E-131.E-121.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-04-40-30-20-10010203040Gatevoltage[V]Draincurrent[A]AfterPassivation(SiO2)1.E-131.E-121.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-04-40-30-20-10010203040Gatevoltage[V]Draincurrent[A]AfterS/DetchVTO:Turn-onvoltageVds=10VW/L=40/40DepletionmodeSpin-CoatedIZO-TFTs:I-Vvsprocessstep(BCE-type)S/DetchbyCl2/O2plasma•μ=0.9cm2/Vs•Vth=13.6V•VTO=-10V•S.S=1.2V/dec•Ion/Ioff=1.8x107PrintedElectronicsAsia2009MK-RYU16Uniformity1.E-141.E-131.E-121.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-04-40-30-20-10010203040Gatevoltage[V]Draincurrent[A]5TFTsin4inchareaW/L=