Patent ID: 9546416
Date: 2017-01-17
CPC Classifications: C23C,C30B

Claim:
1. A method of forming a crystalline oxide semiconductor film, comprising: depositing a crystalline film comprising an oxide semiconductor by a sputtering method with a condition that a substrate is heated to a temperature of higher than or equal to a first temperature and lower than a second temperature and is irradiated with an energy line so that a temperature of a part of the substrate is higher than or equal to the second temperature, wherein the crystalline film comprising the oxide semiconductor comprises a first portion which is crystalline, wherein the crystalline film comprising the oxide semiconductor comprises a second portion over the part of the substrate, wherein the first portion includes the second portion, wherein an area of the first portion is larger than an area of the second portion, wherein the first portion is a place where the substrate is heated in the depositing step, wherein the second portion is a place where the substrate is irradiated with the energy line in the depositing step, wherein the first temperature is a temperature at which crystallization of the oxide semiconductor occurs with a stimulation, wherein the second temperature is a temperature at which crystallization of the oxide semiconductor occurs spontaneously, wherein the part of the substrate has a typical length of 1 nm to 1 μm, and wherein the typical length is a square root of a value obtained by dividing an area of the part by a circular constant.