Fab-Process-flow

AOSConfidentialAOSConfidentialWaferFabProcessDeviceDesignJuly21,2006AOSConfidentialSemiconductorProcessingBasicsSemiconductorProcessingBasics•Photolithography•Dryetching•ImplantanddiffusionAOSConfidentialPowerMOSFETProcessFlowPowerMOSFETProcessFlow--11•Epitaxiallayergrowthonstartingsubstrate•TrenchEtchingandrounding•Gateoxidation.Polysilicondepositionandetchback•BodyImplantanddiffusion•SourceImplantanddiffusion•Dielectricdepositionandanneal.Contactpatterningandetchingsourceandgatecontacts•Metaldepositionandpatterning.Sintercontacts•Passivationdepositionandpatterning.•BackLAPtothinwafer.Backmetaldeposition.AOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessTrenchEtching(RIE)SmoothverticalsidewallsandwellroundedbottomsarekeyfordevicereliabilityAOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessGateoxidation.PolysilicondepositionandetchbackAOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessBodyImplantandDriveSourceImplantandDriveChannelFormationProcessAOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessOxideDepositionContactEtchAOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessThickMetalDepositionDryMetalEtchMetalMetalAOSConfidentialTrenchMOSFETprocessTrenchMOSFETprocessPassivationDepositionandetchBackLapandBackMetalMositure,IonresistanceMechanicalscratchresistancereducesubstrateresistanceAOSConfidentialWaferProbeandAcceptanceWaferProbeandAcceptance
Alltheprocess-criticalstepsliketrenchwidth,depth,contactsizeetcaremonitoredintheFAB.
Oncethemetalison,theprocesscontrolmonitorisprobed.Specialteststructuresprovidedatatomonitorkeyprocessparameterslikethesource,bodyregions,contactresistancesetc.
Thewaferissampleprobed(200-400sites/wafer)andpurchasedbasedonpassingestablishedyieldcriteria.