A semiconductor device including a layer formed without being affected by a stepped ground pattern and a method of fabricating the semiconductor device are disclosed. Cap portions (30) (insulating layers) formed over trenches (13) and covering doped polysilicon (5) have an inclined surface (26) which...http://www.google.de/patents/US5508534?utm_source=gb-gplus-sharePatent US5508534 - Trench gate type insulated gate bipolar transistor
