Rapid Wafering of Wide Bandgap Substrates

OptiCOMP has a non-abrasive wafering technique that will reduce the cost of manufacturing wide bandgap semiconductor substrates, i.e. silicon carbide (SiC), gallium nitride (GaN), AlN and diamond by up to a factor of 2. These materials are very expensive and hard. A top of the line wafer can cost a few thousand dollars. Currently wafers are cut using wire saws. These are heavy and bulky machines that cost up to a million dollars. Up to 50% of the wide bandgap material is lost to dust during wafering. About 500 m worth of materials is lost to make a 500 m thick wafer. It takes up to one week to cut 6” wafer due to the hardness of these materials. Also the diamond wire which is consumable is itself expensive and must be replaced often because it affects the uniformity of the cut. We drive a crack at a depth about 500 m below the surface to separate a wafer from boule. This is fundamentally different from epitaxial lift-off which drives a shallow crack near the surface. OptiCOMP´s technique yields savings in CAPEX, materials, time of wafering and consumables. This project will investigate ways to widen the area of cleavage.