Patent ID: 6750096
Filing Date: 2004-06-15
Classification: H01L

Abstract:
A method for forming a trench with a buried plate, which comprises:forming a trench in a substrate, the trench having a sidewall, an upper region, and a lower region; forming a substantially undoped silicon oxide layer on the trench sidewall in the upper and lower regions of the trench; forming a doped silicate glass fill in the upper and lower regions of the trench; removing the doped silicate glass fill and the substantially undoped silicon oxide layer from the upper region of the trench with an etching process, the doped silicate glass being completely removed through the underlying undoped silicon oxide; and increasing temperature to diffuse dopant from the doped silicate glass fill into the substrate through the substantially undoped silicon oxide layer and to form a buried plate in the substrate in the lower region of the trench.