Selective formation of a compound comprising a semi-conducting material and a metallic material in a substrate through a germanium oxide layer

A method for fabricating an electronic component, comprising at least one step of selective formation of at least one area made from a compound comprising a semi-conducting material and a metallic material in a substrate made from semi-conducting material, said step comprising at least successively:

• forming a germanium oxide layer of a thickness comprised between 3 nm and 5 nm on a part of a surface of the substrate and a silicon oxide layer on the rest of said surface,
• depositing, on the oxide layers, a layer formed by a metallic material whose oxide is thermodynamically more stable than germanium oxide and less stable than silicon oxide,
• thermal annealing at a preset temperature to obtain reduction of the germanium oxide by said metallic material followed by formation of said area, at the level of said part of the surface of the substrate, and
• removing the layer of metallic material.