A method of manufacturing a semiconductor device includes forming a conductive layer below a plate layer, forming a molded structure on the plate layer, forming channel layers extending in the molded structure in a direction perpendicular to an upper surface of the plate layer, forming a metal layer on the channel layers, forming a metal silicide layer on respective tops of the channel layers using the metal layer, applying an electric field to crystallize the channel layers using the metal silicide layers, and removing the conductive layer.

A method for forming a metal oxide layer with high carrier mobility. The method for forming a metal oxide layer includes a first step of forming a first amorphous film, a second step of forming a first crystallized film from the first amorphous film by first heat treatment, a third step of removing a part of the first crystallized film by wet etching to form a seed crystal layer, a fourth step of forming a second amorphous film over the seed crystal layer, and a fifth step of forming a second crystallized film from the second amorphous film by second heat treatment. Each of the first amorphous film, the first crystallized film, the seed crystal layer, the second amorphous film, and the second crystallized film includes indium and oxygen. The first crystallized film includes crystal grains having random orientations. The seed crystal layer has a first crystal orientation with respect to a formation surface. The second crystallized film is formed of crystal grains having the first crystal orientation.