| abstract |
It is an object to provide a method for manufacturing a highly reliable semiconductor device having a thin film transistor formed using an oxide semiconductor and having stable electric characteristics. The semiconductor device includes an oxide semiconductor film overlapping with a gate electrode with a gate insulating film interposed therebetween; and a source electrode and a drain electrode which are in contact with the oxide semiconductor film. The source electrode and the drain electrode include a mixture, metal compound, or alloy containing one or more of a metal with a low electronegativity such as titanium, magnesium, yttrium, aluminum, tungsten, and molybdenum. The concentration of hydrogen in the source electrode and the drain electrode is 1.2 times, preferably 5 times or more as high as that of hydrogen in the oxide semiconductor film. |