Method for manufacturing a free-standing substrate made of monocrystalline semiconductor material

A method for manufacturing a free-standing substrate made of a semiconductor material, which comprises:

• providing a first assembly by bonding of a nucleation layer of a first material to at least one intermediate bonding layer present on a support of a second material at a bonding interface being defined and located between facing surfaces of the nucleation layer and the intermediate bonding layer of the support, wherein the nucleation layer is applied onto the intermediate bonding layer of the support by direct bonding with molecular adhesion;
• growing, by epitaxy on the nucleation layer, a substrate of a layer of a third material to form a second assembly with the substrate attaining a sufficient thickness to be free-standing, with at least the substrate being heated to an epitaxial growth temperature, wherein the third material is a wide bandgap material;
• and
• selecting the coefficients of thermal expansion of the second and third materials to be different from each other by a thermal expansion differential, determined as a function of the epitaxial growth temperature or subsequent application of external mechanical stresses, such that, as the second assembly cools from the epitaxial growth temperature, stresses are induced in the bonding interface to facilitate detachment of the nucleation layer and the substrate from the intermediate bonding layer and the support.

A method for manufacturing a free-standing substrate made of a semiconductor material, which comprises:

• forming a nucleation layer by implantation of an atomic species into a source substrate to a defined depth to form an embrittled zone that defines a boundary of the nucleation layer from a remainder of the source substrate;
• providing a first assembly by bonding the nucleation layer of a first material to a support of a second material, at a bonding interface being defined and located between facing surfaces of the nucleation layer and the support;
• detaching the nucleation layer at the embrittled zone to remove the remainder of the source substrate and provide the nucleation layer bonded to the support;
• growing, by epitaxy on the nucleation layer, a substrate of a layer of a third material to form a second assembly with the substrate attaining a sufficient thickness to be free-standing, with at least the substrate being heated to an epitaxial growth temperature;
• and
• selecting the coefficients of thermal expansion of the second and third materials to be different from each other by a thermal expansion differential, determined as a function of the epitaxial growth temperature or subsequent application of external mechanical stresses, such that, as the second assembly cools from the epitaxial growth temperature, stresses are induced in the bonding interface to facilitate detachment of the nucleation layer and the substrate from the support.