METHOD FOR PRODUCING A COMPOSITE STRUCTURE COMPRISING A THIN MONOCRISTALLINE LAYER ON A CARRIER SUBSTRATE

The invention relates to a process for manufacturing a composite structure comprising a thin layer made of a first single-crystal material positioned on a support substrate. The process comprises:a step a) of providing a donor substrate (10) composed of the first single-crystal material having a front face (10a) and a back face (10b),a step b) of providing a support substrate (20) having a front face (20a), a back face (20b), an edge (20c) and a first alignment pattern (21) on one of said faces or on the edge,a step c) of heat treatment applied at least to the donor substrate (10), under a controlled atmosphere and at a temperature capable of bringing about a surface reorganization on at least one of the faces (10a, 10b) of said substrate (10), the surface reorganization giving rise to the formation of first steps (13) of nanometric amplitude, which are parallel to a first main axis (P1),a step d) of assembling the donor substrate (10) and the support substrate (20) comprising, before the substrates (10, 20) are brought into contact, an optical alignment, to better than ±0.1°, between a locating mark (12) indicating the first main axis (P1) on the donor substrate (10) and at least one alignment pattern (21, 22) of the support substrate (20),a step e) of transferring a thin layer (100) from the donor substrate (10) onto the support substrate (20).