Patent ID: 7713369

Claim:
A method of preparing a thin layer carrying at least a part of a device, the method comprising: providing a substrate having a surface; providing a layer configured to form at least a part of the thin layer and having a first surface and a second surface opposite to the first surface; applying a surface treatment to at least one of the surface of the substrate or the first surface of the layer; forming a detachable bonded interface between the surface of the substrate and the first surface of the layer, wherein the surface treatment is applied so as to create within the bonded interface, a first interface region and a second interface region surrounding the first interface region, the first interface region having a first level of mechanical strength which is greater than zero, and the second interface region having a second level of mechanical strength significantly greater than the first level of mechanical strength; and forming at least a part of a device on the second surface of the layer, wherein the first and second levels of mechanical strength are sufficient to prevent the interface from detaching during this step, and whereby the thin layer and the substrate may be subsequently detached at the bonded interface.