US Patent 7868326 Field effect transistor

A novel field-effect transistor is provided which employs an amorphous oxide. In an embodiment of the present invention, the transistor comprises an amorphous oxide layer containing electron carrier at a concentration less than 1×10−18/cm3, and the gate-insulating layer is comprised of a first layer being in contact with the amorphous oxide and a second layer different from the first layer.