Semiconductor device and method for manufacturing the same

摘要

To manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor. An oxide semiconductor film is deposited by a sputtering method with the use of a polycrystalline sputtering target. In that case, partial pressure of water in a deposition chamber before or in the deposition is set to be lower than or equal to 10−3 Pa, preferably lower than or equal to 10−4 Pa, more preferably lower than or equal to 10−5 Pa. Thus, a dense oxide semiconductor film is obtained. The density of the oxide semiconductor film is higher than 6.0 g/cm3 and lower than 6.375 g/cm3.

主权项

1. A semiconductor device comprising:
a gate electrode layer; a gate insulating layer over the gate electrode layer; a non-single-crystal oxide semiconductor film as a channel formation region over the gate insulating layer; and an insulating layer over the channel formation region, wherein the non-single-crystal oxide semiconductor film comprises a crystal part, wherein a concentration of chlorine in the non-single-crystal oxide semiconductor film is lower than or equal to 2×1018 atoms/cm3, and wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm3.