Method for producing a substrate for the epitaxial growth of a layer of a galium-based III-N alloy

A method of fabricating a substrate for epitaxial growth of a layer of gallium nitride (GaN), of aluminum gallium nitride (AlGaN) or of indium gallium nitride (InGaN), comprising the following successive steps:

• providing a single-crystal silicon-carbide donor substrate;
• implanting ionic species into the donor substrate so as to form a weakened region that defines a thin layer of single-crystal SiC to be transferred;
• bonding the donor substrate to a first receiver substrate via a bonding layer;
• detaching the donor substrate along the weakened region so as to transfer the thin layer of SiC to the first receiver substrate;
• performing epitaxial growth of a layer of semi-insulating SiC having a thickness greater than 1 μm on the thin layer of SiC;
• bonding the layer of semi-insulating SiC to a second receiver substrate, the second receiver substrate having a high electrical resistivity;
• removing at least one portion of the bonding layer so as to detach the first receiver substrate;
• and
• removing the transferred thin layer of single-crystal SiC, so as to uncover the layer of semi-insulating SiC.