JPS6461061A - A-si thin film transistor - Google Patents

Abstract

PURPOSE:To reduce a current between a drain and a source at the time of nonapplying a gate voltage by employing as a gate insulating film of a thin film transistor having an a-Si layer an Al2O3 film between source, drain electrodes S, D and a gate electrode G. CONSTITUTION:A drain electrode D and a source electrode S are formed in thickness of approx. 1000Angstrom on a glass substrate 1. To form an ohmic contact between an a-Si thin film 3 and source, drain electrodes S, D, ohmic contact layers 2s, 2d made of n<+> type a-Si film are laminated approx. 300-500Angstrom thick. Further, the film 3 as an active layer is formed approx. 1000Angstrom thick. An Al2O3 film is formed as a gate insulating film 4 approx. 1000-1500Angstrom thick on the film 3. A gate electrode G is formed on the film 4. Then, in order to diffuse aluminum in the film 3, it is annealed.