SOI structure, for merged logic DRAMs, is produced by forming a protective side wall over a trench side wall oxide layer prior to trench filling

摘要

SOI structure production, by forming a protective side wall over a trench side wall oxide layer prior to trench filling, is new. A planar SOI structure, with regions without covered oxide, is produced on a substrate, consisting of a silicon wafer, an oxide layer, a silicon layer and a nitride layer, by forming a trench down to the silicon wafer, forming oxide layers on the trench bottom and side wall, forming a protective side wall over the side wall oxide layer and part of the bottom oxide layer, removing the bottom oxide layer except for the portion under the protective side wall and filling the trench with a semiconductor. An Independent claim is also included for an SOI structure produced by the above process.