Fast turn-off power semiconductor devices

摘要

A layer (30) of silicon highly doped with n-type dopant (arsenic or antimony) atoms is covered by moderately doped (31) and lightly doped (32) layers. A p-emitter region (60) forms a p-n junction (62) with the lightly doped layer. A dielectric layer of silicon dioxide (36) surrounds a p-type heavily doped polysilicon layer (64) that contacts the p-emitter region and an additional metal layer (66) is provided directly overlying and contacting the polysilicon layer.