| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transistor in which a channel is formed on an oxide semiconductor, and which has stable electric characteristics, suppress fluctuation of a threshold voltage of the transistor in which the channel is formed on the oxide semiconductor, and provide a normally-off type switching element having positive threshold voltage in the n-channel type transistor in which the channel is formed on the oxide semiconductor.SOLUTION: A base insulation layer is formed on a substrate, an oxide semiconductor layer is formed on the base insulation layer, a first gate insulation layer is formed on the oxide semiconductor layer, a second gate insulation layer is formed on the first gate insulation layer by the sputtering method or the atomic layer deposition method at the substrate temperature of 100°C or higher and a gate electrode layer is formed on the second gate insulation layer.</p> |
