Trench isolation process and structure

摘要

A structure and method for forming an isolation wall in an etched trench are described. The trench walls are covered by a thin silicon oxide layer and the trench conformally filled with an oxy-nitride mixture having a particular range of composition so as to produce a neutral to slight tensile stress in the oxy-nitride relative to silicon. The structure is very simple to fabricate and creates fewer defects in the silicon substrate than prior art techniques. Buried voids in the filled trench are eliminated.