MANUFACTURE OF THIN FILM TRANSISTOR

摘要

PURPOSE:To reduce the threshold voltage by a method wherein oxide films are prepared by glow discharge through the mixture of nitrogen monoxide gas with silane gas. CONSTITUTION:A gate electrode 2 is formed on a substrate 1 with a flat surface, and a gate oxide film 3 and a semiconductor film are successively formed by plasma CVD and then patterned into a semiconductor layer 4. The gate oxide film obtained a thickness of 2,000Angstrom by glow discharge deposition in the mixed gas of nitrogen monoxide with the silane with a plasma CVD apparatus. Next, a hydrogenated amorphous Si semiconductor layer 3,000Angstrom thick is formed by glow discharge with silane gas. A source electrode 5 and a drain electrode 6 are produced by depositing Al by sputtering and then patterning. An oxide film 7 is formed as the protection film of the TFT. This manner reduces the threshold voltage and allows no hysteresis and no variation with time, and can keep leakage current to low level.