A semiconductor device having a trench structure, the use of a semiconductor device with a trench structure and method for manufacturing a semiconductor device with a trench structure

摘要

The insulating layer (7) extends from the inner surface of the buried trench (13) to the main surface of the semiconductor substrate (1). On the insulating layer is formed a conductive film (8) and extends from the buried trench inside to the surface of the semiconductor surface. The thickness of the insulating layer, located at a top corner region (7a) of the buried trench side wall and covered by the conductive film, is greater than that of the insulating layer on the side wall of the buried trench outside of the top corner region. The insulating layer is of silicon oxide and the conductive film is of polycrystalline silicon.