Method of driving amorphous silicon thin film transistor

Abstract

Abstract PURPOSE:To prevent degradation of characteristics of a transistor due to irradiation with light, by applying a large voltage across a source and a drain compared with the voltage which causes the area therebetween to be in an insulating state. CONSTITUTION:In a thin film transistor TFT, a n type amorphous silicon hydride (a -Si :H) 4 is so formed under both a source 1 and a drain 2 as to be in ohmic contact with a TFT active layer 6. And, a gate 3 is biased in the reverse direction with respect to ON state so that the transistor is turned into OFF state. Now, the reverse biase is so setted that the voltage thereof is large compared with the voltage which generally causes the area between the source and the drain to be in an OFF state. As a result, an Si-Si bond which was strained in ON state can be restored to the original state thereof. Even if the bond is broken, when the reverse biase is applied, the bonds which were broken can be again close nearly each other, thereby the probability of their being bonded is increased. Accordingly, the photodegradation of an amorphous silicon can be prevented effectively, and the TFT with large mobility of carrier can be still kept operated even under the condition of strong irradiation with light.

Inventors

• 👤 Shinichiro Ishihara
• 👤 Seiichi Nagata

Bibliographic Details