wet-etch

WetEtchUnitProcessIntroductionWetcleanPre-cleanoffurnaceEQ:Wetbench(52PCS/2LOT)+IPADRYProcess:ChemicalSPMDHFAPMHPMConcentrationH2SO4:H2O2=4:1HF:H2O=1:50NH4OH:H2O2:H2O=1:2:10HCL:H2O2:H2O=1:1:5Temperature110C23C70C60CMostyieldlosswasattributedtocontamination,andthemosteffectivecleaningtechnologyiswetclean.SPM:removeOrganicsparticle,suchasphotoresistDHF:removenativeoxideandHydrophobicsurfaceproducedAPM:Removeparticlesfromsiliconsurfaces,HigherTemperatureaffectSisurfaceroughnessandSiO2etchingHPM:RemovemetallicimpuritiesfromwafersWetcleanSPMreactionprincipleSPM(SulfuricPeroxideMixture)H2SO4:H2O2=4:1,110+/-5CFunction:Organic/PRresidueremovalMechanism:H2SO4+H2O2HO-(SO2)-O-OH+H2OHO-(SO2)-O-OH+-(CH2)nCO2+H2ONote：UsehotQDR(QuickDumpRinse)torinseoffviscousH2SO4onwafersWetcleanDHFreactionprincipleDHFuseinCSMC:DHF100:1(25℃±0.5℃)/DHF50:1(23℃±0.5℃)/DHF15:1(25℃±0.5℃)Function:Oxideetch,NativeOxideRemovalSiO2/BPSGetchingmechanismSiO2ismainlyetchedbyHF2-SiO2+2HF2-+2H3O+SiF4+4H2OSiF4+2HFH2SiF6(inHFsolution)BPSGismainlyetchedbyHFB2O3+6HF2BF3+3H2ONote：1.BOE/HF会etchwafer表面SiO2,所以Bath,Chunk,WaferGuide材料不能用quartz，只能用PTFE。2.BOE/HF槽后不能用QDR，只能用OR,wafer表面会hydrophobic,容易吸附particle。WetcleanAPMreactionprincipleSolutionoxidizesurfaceorganicsanddissolvessolublecomplexesformed.PHishighLowstabilityofmetalimpuritiesNH4OHDissolvesSiO2andetchesSiH2O2Oxidizer,formslayerofchemicaloxideDepositionofsomespeciesofmetalsonoxide(e.g.Fe,Ca)OxidationDissolutionSurfaceetchingElectricalrepulsionOxidationmechanismElectricalrepulsionmechanismWetcleanHPMreactionprincipleHPM(HCL:H2O2:H2O=1:1:5)60℃±5C,HCl:H2O2:H2OFunction:IonicandMetallicContaminationRemovalSC2providesalowpHenvironment.Alkalineions(Na,K,Limetals),hydroxideofAl,Mg,Fe,Zn(insolubleinNH4OHSC1),andresidualtracemetal(Au/CunotcompletelydesorbedbySC1)willbedissolvedinSC2.WetcleanMonitoritemsDefect&particleUniformitytopointtopointThermaloxEtchrateContaminationApplicationPre-cleanbeforefurufaceWetcleanEKCCleanEQ:Wetbench(52PCS/2LOT)+IPADRYProcess:removepolymer(onlyforBEOL)ChemicalEKCIPATemperature70CNormaltemperatureVIAPADALWetclean1、EKC成份（以EKC265为例）：（1）羟胺Hydroxylamine（HDA）；（2）2-（2-氨基乙氧基）乙醇2-（2-aminoethoxy)ethanol（DGA）；（3）邻苯二酚Catechol；（4）水Water；2.EKC作用机理:（1）分解Reduction最主要的作用（2）螯合Chelation（3）溶解DissolutionH2N-CH2-O-CH2-CH2-OHCNH2ROHRDGAHDA3、各成份作用：Wetclean（1）：HDA、DGA螯合Polymer（2）：HDA、DGA分裂PolymerRMRCNH2HORRH2OR-NH2RCOROH2ORCNH2OROH+易于溶解对Metal产生腐蚀作用H2O：相当于活化剂，不可或缺；M=AlCuSiWetclean4、各成份作用：OOHHMHOOH邻苯二酚(Dihydroxy-benzene)邻苯二酚和metal结合并停留在metal表面，保护metal不被HDA、DGA侵蚀。在IPA或H2O中容易还原M=AlCuWetcleanEKCMonitoritemsDefect&particleTINERAbilityofpolymerremovalApplicationCleanaftercontactetchCleanaftermetaletchCleanafterpadetchWetSIN-removalwetSINremovalEQ:Wetbench(52PCS/2LOT)+IPADRYProcess:ChemicalDHFH3PO4ConcentrationHF:H2O=1:10086%H3PO4Temperature25C165CDHF:removeOXontheLPSIN.H3PO4:etchLPSINandhighselectivitytooxideWetSin-removal1、反应方程式：该反应是可逆反应，增加H2O可以使反应正向进行，从而提高腐蚀速率。NO↑+NO3-+H2PO4-WetSin-removal2、腐蚀速率和温度、水份浓度的关系：1）、温度越高，腐蚀速率越高。2）、水份含量越高，腐蚀速率越高。WetSin-removal3、浓度与沸点的关系：86%H3PO4的沸点大约是165℃.WetSin-removal4、H3PO4对SIO2有腐蚀作用吗？H3PO4对SIO2的腐蚀速率是其对SIN的1/10为什么实际在SIN全剥后，这一FOXLOSS没有得到体现？3Si3N4+27H2O+4H3PO44(NH4)3PO4+9H2SIO32H3PO4+3SiO23H2SIO3+P2O5WetSIN-removalSINremovalMonitoritemsDefect&particleThermaloxERLPSINERUniformitytopointtopointApplicationLPSINremoveWetPRstripwetPRstripEQ:Wetbench(52PCS/2LOT)+IPADRYProcess:ChemicalSPMAPMConcentrationH2SO4:H2O2=10:1NH4OH:H2O2:H2O=1:2:10Temperature120C40CSPM:removePRAPM:removeparticle