Patent ID: 6964914
Filing Date: 2005-11-15
Classification: H01L,Y10S

Abstract:
1. A method for manufacturing a free-standing substrate made of a semiconductor material, which comprises: preparing a first assembly by bonding a nucleation layer of a first material to a support of second material, with a removable bonding interface being defined and located between facing surfaces of the nucleation layer and 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 removable bonding interface to facilitate detachment of the nucleation layer and the substrate from the support, wherein the substrate is gallium nitride, aluminum nitride or diamond.