STRUCTURE OF THIN FILM TRANSISTOR

摘要

PURPOSE:To perform a liquid crystal display of high quality by employing a-Si Sn:H for a light shielding film material to compose a light shielding film having no capacity coupling, thereby obtaining a TFT having no AC noise. CONSTITUTION:An a-Si TFT 21 has a gate electrode 23, a gate insulating film 24, an a-Si film 25 as an operating semiconductor layer, a source electrode 26 and a drain electrode 27 formed on an insulating substrate 22, and a protecting film 28 and a light shielding film 29 are formed on the surface. The film 29 is composed of an a-Si Sn:H thin film with light absorbing property. In other words, the film 29 shields the TFT. Since the a-Si Sn:H for forming the film 29 has high resistance, the film 29 reduces a capacity coupling between source and drain electrodes through the light shielding film.