| abstract |
To provide a transistor having excellent electrical characteristics. A semiconductor device having a semiconductor, which has first through third portions, a first insulator on the semiconductor, and a first conductor on the first insulator. The first conductor has a region overlapping with the first portion. The first conductor has a region having tungsten and one or more elements selected from silicon, carbon, germanium, tin, aluminum, and nickel. The second portion has one or more of phosphorus, boron, nitrogen, argon, and xenon. The third portion has one or more of phosphorus, boron, nitrogen, argon, and xenon. The first conductor has an amorphous region. |