摘要 |
Disclosed is a semiconductor device with a transistor in which an oxide semiconductor is used. An insulating layer on a back channel side of the oxide semiconductor layer has capacitance of lower than or equal to 2×10−4 F/m2. For example, in the case of a top-gate transistor, a base insulating layer has capacitance of lower than or equal to 2×10−4 F/m2, whereby the adverse effect of an interface state between the substrate and the base insulating layer can be reduced. Thus, a semiconductor device where fluctuation in electrical characteristics is small and reliability is high can be manufactured. |