A SIMPLE METHOD TO CONTROL BIPOLAR POLYSILICON EMITTER INTERFACIAL OXIDE

Polysilicon emitters are prevalent in today's advanced BiCMOS processe s. Electrical and materials analysis has been used to demonstrate the increase in npn current gain, for polysilicon emitters, with an increa sing interfacial ''oxide'' thickness. This interfacial ''oxide'' thick ness has been tailored by the polysilicon push temperature into an LPC VD vertical thermal reactor. The interfacial ''oxide'' thickness has b een shown to affect the npn current gain by modulating the base curren t without significantly impacting the collector current.