Patent ID: 7888235
Filing Date: 2011-02-15
Classification: C30B,H01L,Y10S

Abstract:
1. A method for fabricating a semiconductor substrate which comprises: providing a source substrate including a seed layer and a weakened zone, wherein the source substrate and the seed layer are made of a first material having a first thermal expansion coefficient and; detaching in a first detachment step the seed layer from the source substrate at the weakened zone; transferring the seed layer on to a support substrate at an adhesion interface, wherein the support substrate is made of a second material having a second thermal expansion coefficient; depositing a working layer on the seed layer to form a composite substrate, wherein the working layer is made of a third material that has a third thermal expansion coefficient; and detaching in a second detachment step the seed layer and the working layer from the composite substrate at the adhesion interface, wherein the material and thickness of the seed layer are selected so that thermal expansion of the support substrate and of the working layer deforms the seed layer; and wherein the thermal expansion coefficients of the first, second and third materials are different.