Insulated gate field effect transistor integrated circuits with silicon gates

The Silicon Gate Technology is a new approach to fabricating insulated gate field effect transistor circuits, in which the metal gate electrode is replaced by a doped, silicon electrode. The work function difference between the gate electrode and semiconductor bulk will now be determined by the doping of the gate electrode. This leads to normally off p-channel devices with threshold voltages typically between 1.1 v and 2.5 v on material with 1000Å gate oxide. It is a self-aligned gate structure and has a buried-gate electrode which allows crossover of gate regions and closer spacing of source-drain contact. The fabrication needs 4 masking steps and was found to be compatible with existing planar technology.