Donor substrate for the transfer of a thin layer and associated transfer method

A donor substrate for transferring a single-crystal thin layer made of a first material, onto a receiver substrate, the donor substrate having a front side and a back side, and comprising:

• a buried weakened plane delimiting an upper portion and a lower portion of the donor substrate;
• in the upper portion, a first layer on the side of the front side, a second layer adjacent to the buried weakened plane, and a stop layer between the first layer and the second layer, the first layer being composed of the first material and intended to form the single-crystal thin layer, the stop layer being formed of a second material capable of providing selective etching with respect to the first material;
• and
• an amorphized sub-portion, made amorphous by ion implantation, having a thickness less than that of the upper portion, and including at least the first layer, the second layer comprising at least one single-crystal sub-layer, adjacent to the buried weakened plane, the sub-layer being intended to form a recrystallization seed for the amorphized sub-portion.