Patent ID: 7541244
Filing Date: 2009-06-02
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor device having a trench gate, comprising: providing a semiconductor substrate having a trench etch mask thereon; forming a first trench in the semiconductor substrate using the trench etch mask as a shield; doping impurities into the semiconductor substrate along the first trench to form a doped region; deepening the first trench to define a second trench in the semiconductor substrate so as to the semiconductor substrate of a bottom of the second trench free of the doped region; forming a single gate insulating layer on a sidewall and a bottom of the second trench simultaneously, wherein a first portion of the single gate insulating layer on the sidewall of the second trench is thicker than a second portion of the single gate insulating layer on the bottom of the second trench; and forming a trench gate in the second trench.