A process is taught which provides very shallow conductive regions in a semiconductor material by the formation of a fixed charge placed in an overlying dielectric layer which induces an inversion region in the underlying semiconductor. The inversion region so formed is used as a MOSFET drain extension...http://www.google.com.tw/patents/US5108940?utm_source=gb-gplus-share專利 US5108940 - MOS transistor with a charge induced drain extension
