Patent attributes
Multiple wide bandgap semiconductor wafers, each having active circuitry and an epitaxially formed backside drain contact layer, may be constructed from a single bulk semiconductor substrate by: forming foundational layers on the top of the bulk substrate via epitaxy; forming active circuitry atop the foundational layers; laser treating the backside of the bulk substrate to create a cleave line in one of the foundational layers; and exfoliating a semiconductor wafer from the bulk substrate, where the exfoliated semiconductor wafer contains the active circuits and at least a portion of the foundational layers. Wafers containing the foundational layers without complete active devices may be produced in a similar manner. The foundational layers may comprise a drain contact layer and a drift layer, and may additionally include a buffer layer between the drain contact layer and the drift layer.
