In manufacturing a transistor, a doping mask is formed above a substrate. The doping mask is constructed, so that a first region of the substrate for serving as a source in the transistor and a second region of the substrate for serving as a drain in the transistor are substantially shielded. Once the...http://www.google.ca/patents/US6153454?utm_source=gb-gplus-sharePatent US6153454 - Convex device with selectively doped channel
