Method for manufacturing a SOI substrate associating silicon based areas and GaAs based areas

Method for manufacturing an SOI substrate associating at least one silicon based area (4′) and at least one GaAs based material area (8) at the thin layer (1) of the SOI substrate, the SOI substrate comprising a support (2) having a silicon face supporting successively a layer (3) of dielectric material and a thin silicon based layer (4), the method being characterised in that it comprises the following steps:

• supply of a SOI substrate (1) comprising a support (2) having a silicon face mismatched by an angle of between 2° and 10° inclusive, the thin silicon based layer (4) being oriented parallel to the plane (001) or (010) or (100) or (110) or (101) or (011) or (111),
• preservation of at least one area (4′) of the thin silicon based layer (4),
• elimination of at least one non-preserved area of the thin layer of silicon until the layer (3) of dielectric material is revealed,
• opening, in said non-preserved area, of the dielectric material layer (3) until the silicon face of the support (2) is revealed,
• growth, from the silicon of the support (2) revealed by said opening (6) and by liquid phase epitaxy or by lateral epitaxy, of mismatched germanium (7) on the dielectric material layer revealed,
• growth of the GaAs based material (8), from mismatched germanium (7) obtained in the preceding step.