Patent attributes
An object is to control composition and a defect of an oxide semiconductor. Another object is to increase field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with off current suppressed. The oxide semiconductor is represented by InMO3(ZnO)n (M is one or a plurality of elements selected from Ga, Fe, Ni, Mn, Co, and Al, and n is a non-integer number of greater than or equal to 1 and less than 50) and further contains hydrogen. In this case, the concentration of Zn is made to be lower than the concentrations of In and M (M is one or a plurality of elements selected from Ga, Fe, Ni, Mn, Co, and Al). In addition, the oxide semiconductor has an amorphous structure. Here, n is preferably a non-integer number of greater than or equal to 50, more preferably less than 10.
