SUBSTRATES FOR SEMICONDUCTOR DEVICES

摘要

A method of manufacturing a composite substrate for a semiconductor device, the method comprising: selecting a wafer comprising single crystal silicon or silicon carbide, the wafer having a thickness in a range 0.3 mm to 2.0 mm; growing a polycrystalline diamond layer on the wafer using a chemical vapour deposition technique at a first temperature in a range 700°C to 1200°C to form a composite comprising the wafer bonded to the polycrystalline diamond layer, the polycrystalline diamond layer having a thickness in a range 50 µm to 150 µm; heating or cooling the composite to a second temperature to generate a strain field in the wafer which is sufficient to enable cleavage of the wafer at a distance of 15 µm or less from an interface with the polycrystalline diamond layer while being low enough to avoid the wafer fragmenting and/or the polycrystalline diamond layer cracking; and cleaving the wafer at a distance of 15 µm or less from an interface with the polycrystalline diamond layer to release strain energy and form a composite substrate comprising the polycrystalline diamond layer directly bonded to a cleaved layer comprising single crystal silicon or silicon carbide, the cleaved layer having a thickness of 15 µm or less.