Patent ID: 6436778
Filing Date: 2002-08-20
Classification: H01L

Abstract:
A process for fabricating a semiconductor device comprising:providing a semiconductor substrate having a core region and a peripheral gate region, at least one shallow trench isolation region in the semiconductor substrate, at least one nitrogen-contaminated region in the peripheral gate region of the semiconductor substrate, a tunnel oxide layer overlying the semiconductor substrate, a first polysilicon layer overlying the tunnel oxide in the core region, and an ONO layer overlying the first polysilicon layer in the core region; growing a sacrificial oxide layer overlying the nitrogen-contaminated region in the peripheral gate region, the sacrificial oxide layer being formed immediately on top of the tunnel oxide layer, wherein oxygen from within the sacrificial oxide layer diffuses into the nitrogen-contaminated region to form a silicon dioxide region; depositing a photoresist over the core region for protection from a subsequent etch process; subsequently removing the sacrificial oxide layer, the tunnel oxide layer and the silicon dioxide region in the peripheral gate region; and forming a gate oxide layer over the semiconductor substrate in the peripheral region and shallow trench isolation region using a dry oxidation process at a temperature of about 950Â° C.