Doped semiconductor layer forming method

A method of obtaining a doped semiconductor layer, comprising the successive steps of:

• a) performing, in a first single-crystal layer made of a semiconductor alloy of at least a first element A1 and a second element A2, an ion implantation of a first element B which is a dopant for said alloy and of a second element C which is not a dopant for said alloy, to make an upper portion of the first layer amorphous and to preserve the crystal structure of a lower portion of the first layer;
• and
• b) performing a solid phase recrystallization anneal of the upper portion of the first layer, resulting in transforming the upper portion of the first layer into a doped single-crystal layer of said alloy,
• wherein the dopant and non-dopant elements B and C substitute to atoms of element A1,
• wherein, during step a), a complementary implantation of element A2 is performed to compensate for the addition of elements B and C.