Oxide material and semiconductor device

摘要

An object is to provide a material suitably used for a semiconductor included in a transistor, a diode, or the like. Another object is to provide a semiconductor device including a transistor in which the condition of an electron state at an interface between an oxide semiconductor film and a gate insulating film in contact with the oxide semiconductor film is favorable. Further, another object is to manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor in which an oxide semiconductor film is used for a channel. A semiconductor device is formed using an oxide material which includes crystal with c-axis alignment, which has a triangular or hexagonal atomic arrangement when seen from the direction of a surface or an interface and rotates around the c-axis.

主权项

1. A semiconductor device comprising:
a gate electrode; a gate insulating film adjacent to the gate electrode; and a semiconductor layer comprising an oxide material, and being adjacent to the gate insulating film, wherein the semiconductor layer is formed by sputtering while a surface on which the semiconductor layer is to be formed is heated at a temperature of 150° C. or higher; wherein the oxide material comprises a plurality of crystals with c-axis alignment, wherein each of the plurality of crystals comprises the atoms arranged to have a triangular or hexagonal shape in an a-b plane, and wherein one of a direction of an a-axis and a direction of a b-axis of a first crystal of the plurality of crystals is different from that of a second crystal of the plurality of crystals, in the a-b plane.