Modeling andAnalysis ofMetal Interconnect Resi stance ofPowerMOSFETswith Ultra LowOn-Resistance

Theissue ofmetalinterconnect resistance becomes increasingly critical asthepowerMOSFET technology continues toadvance.Thispaperintroduces a three-dimensional finite elementanalysis (FEA)approach tomodeltheinfluence of source metalontheperformance ofpowerMOSFETswithultra lowon-resistance. Various source metalinterconnection designs fortwo commercial discrete packages, theD2PAK and DirectFET, arestudied extensively usingthenewlydeveloped FEA model.Itisfoundthatthenumberandlocation of wirebonds orsolder padsaswellastheinterconnect layout all haveconsiderable impact onthetotal on-resistance ofapower MOSFET. Furthermore, themetalinterconnect resistance imposes another limit onthelowest RDS(On) thatcanbepractically achieved onpowerMOSFETseveninlight oftheever-decreasing silicon-contributed specific on-resistance. I.INTRODUCTION