US Patent 9324791 Semiconductor element

A semiconductor element includes a substrate and a semiconductor layer. The substrate has a first main face and a second main face. The semiconductor layer is formed on a side of one of the first main face and the second main face of the substrate. The substrate has a plurality of isolated processed portions and an irregularity face that runs from the processed portions at least to the first main face of the substrate and links adjacent ones of the processed portions.