A thin film transistor (TFT) has first (lower) and second (upper) gate electrodes which are provided respectively above and under a semiconductor active layer and first and second insulating films (which serve as gate insulating films) provided respectively between the first gate electrode and a semiconductor...http://www.google.de/patents/US5644147?utm_source=gb-gplus-sharePatent US5644147 - Electro-optical device incorporating pixel transistors with plural gate electrodes
