Substrate with determinate thermal expansion coefficient

A structure for electronic, optic or optoelectronic applications comprising an epitaxy substrate consisting essentially of

• a composite support,
• an oxide bonding layer and
• a transfer layer of crystalline material,
• wherein the composite support has a longitudinal plane of symmetry passing though a central layer and parallel to its principal surface and comprises
• a plurality of layers consisting of crystalline or polycrystalline materials including
• the central layer having a first thermal expansion coefficient at a specified temperature T and extending transversely on either side of the plane of symmetry;
• and
• one or more pairs of lateral layers, having substantially identical thicknesses, with the layers of each pair having second thermal expansion coefficients at the temperature T that are different from the first thermal expansion coefficient of the central layer, and
• with the layers of each pair made of materials, thicknesses and arrangements about the central layer to provide the composite support with symmetry of thermal expansion coefficients about the longitudinal plane of symmetry and with an overall thermal expansion coefficient at the temperature T that is sufficiently close to the thermal expansion coefficient of the material of the transfer layer to avoid deflection, and
• wherein the transfer layer is bonded to a lateral layer of the composite support through the oxide bonding layer inserted between them.