Patent ID: 7998836

Claim:
A method of fabricating a gallium nitride-based semiconductor electronic device, the method comprising the steps of: preparing a substrate having a first surface and a second surface, the first surface being configured to deposit a gallium nitride-based semiconductor, the second surface being provided on the side opposite to the first surface; depositing a semiconductor region on the first surface of the substrate into an epitaxial substrate, the semiconductor region comprising at least one gallium nitride-based semiconductor layer; preparing a conductive substrate; bonding the conductive substrate to the epitaxial substrate into a first substrate product such that the semiconductor region is provided between the first surface of the substrate and the conductive substrate; and separating the semiconductor region and the substrate from each other by laser lift-off involving irradiation of the second surface of the substrate with laser light, subsequent to the bonding of the conductive substrate to the epitaxial substrate, to fabricate a second substrate product comprising the conductive substrate and the semiconductor region, wherein the semiconductor region of the second substrate product has an exposed surface; the substrate comprises a support comprising a material different from the gallium nitride-based semiconductor; the support is exposed on the second surface of the substrate; and at least one of a plurality of grooves and a plurality of ridges is arrayed on the second surface of the substrate.