flash_testing

0FlashTestIntroduce1FlashBackEndFlowOverviewFabOut250CBakeIUVEraseWaferSort1250CBakeIIWaferSort2AssemblyFT1BurnIn(150C)FT2QC,MARK…..2FlashBackEndFlowDescription250CBakeI•CatchChargeGain/Lossdefect.•ThehoursforBakediffersfromeachCompany/Product/Design.•SomeCompaniesdonotgothisflow.UVErase•UnifytheVTofeachcell.WaferSort1•VerifytheUserModefunction(BasicErase/Program…).•Redundance.•Verifydeviceperformance(cellVT,Iref…).•UselotsofTestMode(MarginRead,Row/ColumnStress…).250CBakeII•CatchtheVTdropfailurewhichcausedbyChargeGain/Lossfault.•Usually,intheendofCP1thedevicewillbeprogrammedwithCKBDformat.•ThehoursforBakediffersfromeachCompany/Product/Design.3FlashBackEndFlowDescriptionWaferSort2•VerifyRedundanceResult.•MeasureVTdrop(Margintest).Assembly•SameasSRAM,DRAM….FT1•Mostly,onlytestusermode.•Roomtempmostly.BurnIn•Readcycleonly.•Force1.4xVcc.FT2•Mostly,onlytestusermode.•Hottempmostly.•TestSpeed/Timing(Taa,Toe,Tce…).•TestDCLevel(Vih/Vil,Voh/Vol…).4WaferSort1Flow-IStartOpen/ShortInputLeakageHi/LowInputLeakage(A9,OE,RESET=12.5V)OutputLeakageHi/LowIsbTTL/CMOSICCActiveRead/AdjustIrefReadID(MID,PID)ReadIDAutoselectModeChipEraseRowStress(DisturbMode)Sectorprotect/VerifyReadAllFFPgm/AtuoPgmCKBDMarginReadAllZeroSectorunprotect/VerifyReadCKBDHi/LowPgm/AtuoPgmICKBDReadAllZeroColumnStress(DisturbMode)MarginReadCKBDReadAllFFSectorEraseSuspendSectorEraseResumeMultiSectorEraseReadAllFFPgm/AtuoPgmCKBDRARARARARARA5WaferSort1Flow-IITestRowVerificationWriteDataintoTestRowDoneNote•Read/AdjustIrefisnotforAllCompany/Design.•RAprocedureforeachCompany/Productisdifferent.•TestRowVerificationprocedureforeachCompany/Productisdifferent.•ThedatawrittenintoTestRowforeachCompanyisdifferent.•TestModeforeachCompany/Productisdifferent.MarginReadBump6WaferSort2FlowStartOpenShortReadID(MID,PID)MarginReadCKBDReadCKBDChipEraseReadAllFFDone7FT1FlowInputLeakageHi/LowOpen/ShortIsbTTL/CMOSInputLeakage(A9,OE,RESET=12.5V)StartReadAllFFReadID(MID,PID)ICCActiveReadCKBDSectorProtectBitVerifyPgmCKBDDone8FT2FlowInputLeakageHi/LowOpen/ShortIsbTTL/CMOSInputLeakage(A9,OE,RESET=12.5V)StartReadAllFFReadID(MID,PID)ICCActiveReadCKBDwithDclevel(Vih/Vil,Voh/Vol@Hi/Low)SectorProtectBitVerifyReadCKBDwithspeedtest(Tacc,Toe,Tce@Hi/Low)ProgramAllZeroSectorProtectReadCKBDChipEraseReadCKBDChipErasePgmCKBDwithDClevel(Vih/Vil@LowVcc)ReadCKBDSectorErasewithDCLevel(Vih/Vil@LowVcc)ReadFFDoneReadFFSectorUnprotectProgramCKBD9TestItemDescription-1Open/ShortSameasSRAM.InputLeakageHi/LowSameasSRAM.InputLeakage(A9,OE,RESET=12.5V)Mode:NA.Purpose:Intestmode,A9,OE,[e-mail]:1.Vcc=VccMax,AllPins=0V,2.A9,OE,RESET=Force12.5V,measureleakagecurrent.OutputLeakageHi/LowSameasSRAM.IsbTTL/CMOSSameasSRAM.ICCActiveSameasSRAM.10TestItemDescription-2ReadID(MID,PID)Mode:UserModePurpose:ToverifyMID(ManufacturerID),PID(ProductID).Condition:29Series:1.NormalDClevel.2.NeedfourcycleCommandSequenceEx:First(Addr,Data)=Second(Addr,Data).First(555,WAA)=Second(2AA,W55)=Third(555,W90)=Fourth(00,R01)28Series:1.A9=13V,Otherpins:Normallevel.2.Onecyclecommandonly.ReadIDAutoselectModeMode:AutoselectModePurpose:ToverifyMID(ManufacturerID),PID(ProductID).Condition:29Series:1.A9=12V,OtherPins=NormalLevel.2.Onecyclecommandonly.28Series:Onlyusermode11TestItemDescription-3Read/AdjustIrefMode:TestMode.Purpose:Forsomeflashdevice,theIrefcanbeadjustedbyusingtestmode.Condition:PerDesign.ChipEraseMode:TestMode.Purpose:Erasewholedevicebyusingusermode.Condition:29Series:1.NormalDClevel.2.Need6cycleCommandSequenceEx:First(Addr,Data)=Second(Addr,Data).First(555,WAA)=Second(2AA,W55)=Third(555,W80)=Fourth(555,WAA)=Fifth(2AA,55)=Sixth(555,10)3.DQ7,DQ5Polling.28Series:1.Vpp=12V2.Need2cycleCommand:Set_Up_Erase_Cmd(XX,W20)=Erase_Cmd(XX,W20)3.EraseVerifyneeded.12TestItemDescription-4ReadAllFFMode:UserMode.Purpose:Readalloneagainstthewholedevice.Condition:NormalDClevel.SectorProtectMode:TestModePurpose:SetthedeviceintoProtectionMode,inthismode,EraseandProgramisinvalid.Condition:Perdesign.SectorProtectVerifyMode:UserModePurpose:ReadProtectionBitCondition:29Series:1.NormalDClevel.2.Need4cycleCommandSequenceEx:First(Addr,Data)=Second(Addr,Data).First(555,WAA)=Second(2AA,W55)=Third(555,W90)=Fourth(02,R01)28Series:NA.13TestItemDescription-5SectorUnProtectMode:TestModePurpose:SetthedeviceinUnProtectionMode,andinthismode,EraseandProgramisValid.Condition:Perdesign.SectorUnProtectVerifyMode:UserModePurpose:ReadProtectionBitCondition:29Series:1.NormalDClevel.2.Need4cycleCommandSequenceEx:First(Addr,Data)=Second(Addr,Data).First(555,WAA)=Second(2AA,W55)=Third(555,W90)=Fourth(02,R00)28Series:NA.14TestItemDescription-6PgmCKBDMode:UserModePurpose:ProgramCKBDdatatothewholedeviceCondition:29Series:1.NormalDClevel.2.Need4cycleCommandSequenceEx:First(Addr,Data)=Second(Addr,Data).First(555,WAA)=Second(2AA,W55)=Third(555,WA0)=Fourth(PA,PD)3.PA:Addressofmemorylocationtobeprogrammed.4.PD:DatatobeprogrammedatlocationPA.5.DQ7,DQ5Pollingneeded.28Series:1.Vpp=12V2.Need2cycleCommand:Set_Up_Write_Cmd(XX,W40)=Write_Cmd(PA,PD)3.Pr