Process for locally dissolving the oxide layer in a semiconductor-on-insulator type structure

摘要

A process for treating a semiconductor-on-insulator type structure that includes, successively, a support substrate, an oxide layer and a thin semiconductor layer. The process includes formation of a silicon nitride or silicon oxynitride mask on the thin semiconductor layer to define exposed areas at the surface of the layer which are not covered by the mask, and which are arranged in a desired pattern; and application of a heat treatment in a neutral or controlled reducing atmosphere and under controlled conditions of temperature and time to induce at least a portion of the oxygen of the oxide layer to diffuse through the thin semiconductor layer, thereby resulting in the controlled reduction in the oxide thickness in the areas of the oxide layer corresponding to the desired pattern. The mask is formed so as to be at least partially buried in the thickness of the thin semiconductor layer.