Manufacturing method of semiconductor device

摘要

A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming a first crystalline oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface of the first crystalline oxide semiconductor film, over an insulating film; forming a gate insulating film over the first crystalline oxide semiconductor film; adding oxygen to the first crystalline oxide semiconductor film through the gate insulating film, so that an oxide semiconductor film at least a part of which is amorphous is formed; forming a gate electrode layer over the gate insulating film; forming an aluminum oxide film over the gate electrode layer; and performing a heat treatment on the oxide semiconductor film at least the part of which is amorphous to crystallize at least a part of the oxide semiconductor film, so that a second crystalline oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface of the second crystalline oxide semiconductor film is formed.