MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device including an oxide semiconductor with stable electric characteristics and higher reliability.SOLUTION: In a process of manufacturing a transistor with a bottom-gate structure including an oxide semiconductor layer, heat treatment in an atmosphere including oxygen and heat treatment in vacuum are gradually performed as dehydrating or dehydrogenating treatment of the oxide semiconductor layer. At the same time as the heat treatment, short wavelength light is irradiated to promote desorption of hydrogen, OH, or the like. The transistor including the oxide semiconductor on which the dehydrating or dehydrogenating treatment by the heat treatment has been performed in this manner can reduce the instability of electrical characteristics before and after the light irradiation or bias-thermal stress (BT) test.