Process of manufacturing a trench gate semiconductor device

摘要

A process of manufacturing a trench gate semiconductor device comprises providing a semiconductor material (600,602); placing the semiconductor material in a reaction chamber; forming a trench (606) at a surface of the semiconductor material; growing an oxide lining (608) on the sidewalls and floor of the trench; depositing a polysilicon layer (610) in the trench; etching the polysilicon layer such that a portion (612) thereof remains near a bottom of the trench; etching a portion of the oxide lining from the sidewalls of the trench, leaving a remaining portion of the oxide lining; performing an anisotropic silicon etch to depress the surface of the portion of the polysilicon layer below the surface of the remaining portion of the oxide lining; heating the semiconductor material to form a first oxide layer (618) on the surface of the portion of the polysilicon layer and a second oxide layer (616) on the sidewalls of the trench; removing the first oxide layer; and depositing a polysilicon layer (619) in the trench to form a gate electrode.