A semiconductor device such as a semiconductor layer is formed of a compound semiconductor layer of III-V group such as GaN. In the case where the substrate has not any planes that are easy to cleave which coincides with an easy-to-cleave plane of a semiconductor layer grown on the substrate...http://www.google.de/patents/US5821568?utm_source=gb-gplus-sharePatent US5821568 - Cleaved semiconductor device with {11-20} plane
