Patent ID: 9660044
Date: 2017-05-23
CPC Classifications: H01L

Claim:
1. A power field effect transistor comprising: a semiconductor layer of a first conductivity type, the first semiconductor layer having a first side, a body region of a second conductivity type formed at the first side inside the semiconductor layer, source regions of the first conductivity type formed at the first side within the body region, a patterned gate oxide layer superimposed at the first side on the semiconductor layer with a first opening over the body region, a patterned polysilicon layer superimposed to at least a portion of the patterned gate oxide layer, a lateral oxidized polysilicon layer at a sidewall of the patterned polysilicon layer, the sidewall facing towards a the first opening in the patterned gate oxide layer, wherein a lateral thickness (tp_ox) of the lateral oxidized polysilicon layer measured in the lateral direction is thick enough for preventing a premature current injection in the manufactured power field effect transistor from the patterned polysilicon layer source regions of the manufactured power field effect transistor.