| 摘要 |
PURPOSE:To obtain a TFT characterized by small fluctuation width of a thresh old voltage and excellent reliability, by performing plasma treatment of a sillicon nitride film constituting a gate insulating film by using mixed gas of nitrogen and hydrogen and the like, and laminating semiconductor layers. CONSTITUTION:On a conductor film 12, which functions as a gate electrode, a silicon nitride film 13 comprising silicon and nitrogen as main component is formed as a gate insulating film. A silicon thin film 14, whose main component is silicon, is laminated as a semiconductor layer, and a thin film transistor is manufactured. At this time, plasma treatment of said silicon nitride film is performed by using any one kind of mixed gas among a mixed gas comprising hydrogen gas and nitrogen gas, a mixed gas comprising hydrogen gas, inactive gas and ammonia and a mixed gas comprising inactive gas and ammonia. By the plasma treatment, the quality of the surface of the silicon nitride film becomes excellent as an insulator. The fluctuation in threshold voltage with respect to the applied voltage of on the TFT can be suppressed. Therefore, the stable TFT is obtained. |
