Soitec

Fabrice Gritti

Oleg Kononchuk

Didier Landru

Eric Guiot

Christelle Veytizou

A process for avoiding formation of an Si&#x2014;SiO&#x2014;Henvironment during a dissolution treatment of a semiconductor-on-insulator structure that includes a carrier substrate, an oxide layer, a thin layer of a semiconductor material and a peripheral ring in which the oxide layer is exposed. This process includes encapsulating at least the exposed oxide layer of the peripheral ring with semiconductor material by performing a creep thermal treatment; and performing an oxide dissolution treatment to reduce part of the thickness of the oxide layer. In this process, the semiconductor material that encapsulates the oxide layer has a thickness before the oxide dissolution that is at least twice that of the oxide that is to be dissolved, thus avoiding formation of an Si&#x2014;SiO&#x2014;Henvironment on the peripheral ring where the oxide layer would otherwise be exposed.

Process to dissolve the oxide layer in the peripheral ring of a structure of semiconductor-on-insulator type

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.

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Voiron, France

Fabrice Gritti