SUBSTRATE WITH DETERMINATE THERMAL EXPANSION COEFFICIENT

摘要

A composite support (10) destined to receive a transferred layer (20) of crystalline material, to form a substrate for epitaxy, has a symmetrical longitudinal plane parallel to its principle surfaces and is made up of: - (A) a first central layer (1) having a first coefficient of thermal dilation at a determined temperature (T) and extending transversely either side of the plane of symmetry; - (B) at least one pair of lateral layers (2, 2'), each pair having dispositions in the composite support essentially symmetrical with respect to the plane of symmetry, with second coefficients of thermal dilation at the temperature (T) identical to each other and with essentially identical thickness; and - (C) the materials constituting the layers of the composite support are chosen such that the composite support has a global coefficient of thermal dilation at temperature (T) close to that of the material of the transferred layer. - Independent claims are also included for: - (A) the formation of a layer on a composite support; - (B) the formation of a number of substrates for epitaxy using this method of forming a layer on a composite support; and - (C) a structure made up of the substrate for epitaxy.