Transcription of Chapter 9 Metal-Semiconductor Contacts
1 Semiconductor Devices for Integrated Circuits (C. Hu)Slide 9-1 Chapter 9 Metal-Semiconductor Contacts :metal on lightly doped silicon rectifyingSchottky diodesmetal on heavily doped silicon low-resistanceohmic contactsSemiconductor Devices for Integrated Circuits (C. Hu)Slide Schottky BarriersEnergy Band Diagram of Schottky Contact B Bq Bnq BpEgq BnEcEcEfEfEvEvq BpSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-3 Schottky barrier heights for electrons and holes Bn Bn Bp m Bn Bp Semiconductor Devices for Integrated Circuits (C. Hu)Slide 9-4 Bn Increases with Increasing Metal Work Functionq BnEcEvEfEq M Siq Bn=q M SiSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-5 Bn is typically to VEfEcQuestion Bpq BnEcEvEfEq M Si+ Semiconductor Devices for Integrated Circuits (C. Hu)Slide 9-6 Schottky barrier heights of metal silicide on Simetal-silicon contact Bn BpSemiconductor Devices for Integrated Circuits (C.)
2 Hu)Slide 9-7 Using CV Data to Determine BAWCqNVWNNkTqEEqqdepsdbisdepdcBnfcBnbi =+= = =Question: How should we plot the CV data to extract bi?EvEvEcEfEfEcq Bnq biq Bnq( bi+ V)qVSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-8 bi, AqNVCsdbi +=dcBnfcBnbiNNkTqEEqq = = Using CV Data to Determine BV/C biSemiconductor Devices for Integrated Circuits (C. Hu)Slide thermionic Emission TheorykTqokTqVkTqVkTqnthxMSnthxnthkTVqnk TVqcBBBBeJeJeeThkqmqnvJmkTvmkTvehkTmeNn == = == ==Efnq( B V)q BqVVEfmEvEcxvthxSemiconductor Devices for Integrated Circuits (C. Hu)Slide Schottky DiodeEfq BEfn> q BqVE Ef = q B q BV = 0 == 0 Efnq B q B >>= 0qV <<= 0VI = 0 0 = 0 = 0eqV/kT = 0 = 0 EfnSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-11 = =+= == kTqVkTqVSMMSnkTqeIIeIIII hkqmKeAKTIB EfEfnq B q BqV = 0 = 0 Schottky DiodeSemiconductor Devices for Integrated Circuits (C.
3 Hu)Slide Applications of Schottky DiodesI BIV IV BkTqkTqVBeAKTIeII = =Semiconductor Devices for Integrated Circuits (C. Hu)Slide 9-13 Switching Power SupplyQuestion: Synchronous RectifierVIIIeqV/kTVoutSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-14No excess carrier application may benefit from that? Applications of Schottky DiodesSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-15 GaAs MESFETQ uestion: Semiconductor Devices for Integrated Circuits (C. Hu)Slide Ohmic ContactsSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-17 SALICIDE (Self-Aligned Silicide) Source/DrainRsRdQuestion:Semiconductor Devices for Integrated Circuits (C. Hu)Slide 9-18dBnNVHndthxdMSonnsemkTqNPvqNJmmhmH = == Ohmic ContactsxxVdBnsdepqNW =dBnNHeP =EvEc, EfEfmEvEc, Ef Bn V BnSemiconductor Devices for Integrated Circuits (C. Hu)Slide 9-19 = dBndBnNHdthxNHMSceNHqvedVdJR Ohmic Contacts
