Method for transferring a useful layer into a supporting substrate

A process for transferring a useful layer to a carrier substrate including a first surface, the process comprising successive steps of:

• a) providing a donor substrate made from a first material selected from a crystalline semiconductor and a piezoelectric material including:
• a first surface,
• a weakened zone comprising implanted species,
• the useful layer, which is bounded by the weakened zone and by the first surface of the donor substrate, is comprised of the first material, and has a first thickness in a direction from the first surface to the weakened zone, and
• an amorphous zone disposed, in the useful layer, parallel to the weakened zone and having a second thickness less than the first thickness;
• b) assembling, on a side of the first surface of the donor substrate and on a side of the first surface of the carrier substrate, the donor substrate with the carrier substrate by bonding, step b) being executed such that the amorphous zone is at least partially facing at least one cavity that is partially bounded by the first surface of the donor substrate;
• and
• c) splitting the donor substrate along the weakened zone so as to reveal the useful layer.

A process for transferring a useful layer to a carrier substrate including a first surface, the process comprising successive steps of:

• a) providing a donor substrate comprising a crystalline first material including:
• a first surface,
• a weakened zone comprising implanted species,
• the useful layer comprising a portion of the crystalline first material of the donor substrate bounded by the weakened zone and by the first surface of the donor substrate, and
• an amorphous zone disposed, in the useful layer, parallel to the weakened zone;
• b) assembling, on a side of the first surface of the donor substrate and on a side of the first surface of the carrier substrate, the donor substrate with the carrier substrate by bonding, step b) being executed such that the amorphous zone is at least partially facing a plurality of cavities that are each partially bounded by the first surface of the donor substrate;
• and
• c) splitting the donor substrate along the weakened zone so as to reveal the useful layer,
• wherein the amorphous zone comprises a plurality of zones each being formed to be surrounded by the crystalline first material, and each partially facing one of the plurality of cavities.