| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor device by providing a semiconductor device including an oxide semiconductor with stable electric characteristics.SOLUTION: In a manufacturing process for a transistor including an oxide semiconductor layer, a gate electrode is formed, an aluminum oxide film and a silicon oxide film and an oxide semiconductor film are formed continuously in an in-line device without exposure to the atmosphere, heating and oxygen addition processes are performed in the same in-line device, the transistor is covered with another aluminum oxide film, a heating process is performed to remove the impurities including hydrogen atoms and thereby forming an oxide semiconductor layer including oxygen over the stoichiometric ratio. In regard to the transistor including the oxide semiconductor film, the change amount of threshold voltage of the transistor before and after the bias-thermal stress test (BT) is decreased and the obtained transistor has the high reliability.SELECTED DRAWING: Figure 4 |
