| abstract |
A transistor that sometimes uses an oxide semiconductor is inferior in reliability compared to a transistor using amorphous germanium. Accordingly, an object of the present invention is to manufacture a semiconductor device having a highly reliable transistor using an oxide semiconductor. An oxide semiconductor film formed by using a sputtering target by a sputtering method, wherein the sputtering target is made of a crystal region having a c-axis parallel to a normal vector of an upper surface, which is produced by mixing a raw material with a composition capable of obtaining a crystal structure. The composition of the oxide semiconductor. |