In manufacturing a GTO, a silicon wafer is cut away along one of the crystal planes indicated by {n11} in Miller indices, and the burried gate or the current channels are so arranged on the crystal plane that at least one longitudinal direction thereof is substantially in parallel with at least one of...http://www.google.se/patents/US4651188?utm_source=gb-gplus-sharePatent US4651188 - Semiconductor device with specifically oriented control layer
