S.o.i.tec Silicon on Insulator Technologies

Zohra Chahra

Nicolas Daval

Patrick Reynaud

Muriel Martinez

Frédéric Metral

Romain Larderet

A method of planarization of a surface of a heteroepitaxial layer by chemical-mechanical polishing the disturbed surface of the heteroepitaxial layer with a polishing pad having a compressibility greater than 2% and less than 15% and a slurry comprising at least 20% of silica particles having an average diameter between about 70 and about 100 nm. This method allows to reach high polishing rates appropriated for eliminating surface defects on heteroepitaxial layers, such as crosshatch patterns, and to achieve, in the same time, a final polish that is desirable to facilitate further operations.

Planarization of a heteroepitaxial layer

The invention relates to a method of forming a layer of elastically unstrained crystalline material intended for electronics, optics, or optronics applications, wherein the method is carried out using a structure that includes a first crystalline layer which is elastically strained under tension (or respectively in compression) and a second crystalline layer which is elastically strained in compression (or respectively under tension), with the second layer being adjacent to the first layer. The method includes a step of diffusion between the two layers so that the differences between the respective compositions of the two layers is progressively reduced until they are substantially the same, so that the two layers then form just a single final layer of crystalline material having a composition which, in aggregate, is uniform, and wherein the respective compositions, thicknesses, and degrees of strain of the two layers are initially selected so that, after diffusion, the material then constituting the final layer no longer, in aggregate, exhibits elastic strain. The diffusion can be accomplished by heat treating the structure.

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Meylan, France

Zohra Chahra