A method of forming complementary metal oxide semiconductor field-effect transistors (CMOSFET) is described wherein the source and drain regions are disposed by ion implantation in a manner substantially perpendicular to the substrate surface in two steps, such that the concentration of impurities increases...http://www.google.es/patents/US4757026?utm_source=gb-gplus-sharePatente US4757026 - Source drain doping technique
