Study And Improvement Of Hydrogenated Amorphous Silicon Tft Devices Electrical Properties Of Drift

Hydrogenated Amorphous Silicon Thin Film Transistor (a-Si:H TFT) technology is mature and widely applies to produce active matrix display devices because of its excellent process uniformity and low fabrication costs in large area glass substrate production. So that it makes sense to introduce a-Si:H TFT which used widely in liquid crystal Display (LCD) to drive organic light emitting diode (OLED) devices. While the disadvantages of a-Si:H TFT such as shift of electrical character, lower effective mobility are need to be solved in order to drive OLED well.An a-Si:H TFT electrical character degradation physical model was proposed in this thesis, which is based on the test and analysis of a-Si:H TFT Id-Vg curve and C-V curve. The model believe that the extra interface state caused by weak Si-Si bond breaking determine the degradation degree of a-Si:H TFT electrical character.To decrease the defect state in the interface between SiN:H and a-Si:H, a rapid thermal anneal process after back channel reactive ion etching experiment is proposed. To decrease the state in the boundary of grain inside the a-Si:H, a thinning a-Si:H film layer experiment is proposed.The a-Si:H TFT electrical character degradation physical model is supported by the experiment result. That the weak Si-Si bond breaking is main cause of the a-Si:H TFT electrical character degradation is confirmed again. Furthermore compare to the grain boundary defect state the interface state between SiN:H and a-Si:H seem to be dominating. the model and the experiment result are useful to the TFT design and production process.