Patent ID: 7413964

Claim:
A method for selecting a bulk silicon substrate of suitable quality for use in a subsequent semiconductor fabrication process, the method comprising: performing a revealing heat treatment on a reference silicon substrate in order to predictively reveal crystalline defects in the reference substrate, the reference silicon substrate selected to have a quality representative of the quality of the bulk silicon substrate, wherein the revealing heat treatment comprises heat treatment conducted in a non-reducing atmosphere at a temperature from approximately 500° C. to approximately 1300° C., determining a quality of the reference substrate in dependence on the number of, and the geographical arrangement of, defects apparent on the surface of the processed reference substrate, and selecting the bulk substrate for use in a subsequent semiconductor fabrication process in dependence on the determined quality of the reference substrate and on the requirements of the subsequent fabrication process; wherein the fabrication process is a silicon-on-insulator process which comprises oxidizing at least a first surface of a bulk substrate to form an insulation layer, implanting atomic species into the bulk substrate to form a zone of weakness that defines a useful layer to be transferred with the insulation layer, bonding the insulation layer of the bulk substrate to a receiving substrate; and detaching the useful layer and insulation layer at the zone of weakness to transfer those layers to the receiving substrate, with the fabrication process repeated a desired number of times on the selected bulk substrate to transfer one or more additional useful layers to other receiving substrate(s).