Patent Number: 7,709,302

Title: Method for manufacturing a semiconductor device

Abstract: A purpose of the invention is to provide a method for leveling a semiconductor layer without increasing the number and the complication of manufacturing processes as well as without deteriorating a crystal characteristic, and a method for leveling a surface of a semiconductor layer to stabilize an interface between the surface of the semiconductor layer and a gate insulating film, in order to achieve a TFT having a good characteristic. In an atmosphere of one kind or a plural kinds of gas selected from hydrogen or inert gas (nitrogen, argon, helium, neon, krypton and xenon), radiation with a laser beam in the first, second and third conditions is carried out in order, wherein the first condition laser beam is radiated for crystallizing a semiconductor film or improving a crystal characteristic; the second condition laser beam is radiated for eliminating an oxide film; and the third condition laser beam is radiated for leveling a surface of the crystallized semiconductor film.

Inventors: Nakajima; Setsuo (Kanagawa, JP)

Assignee: Semiconductor Energy Laboratory Co., Ltd.

International Classification: H01L 21/84 (20060101); H01L 21/20 (20060101); H01L 21/336 (20060101); H01L 21/42 (20060101)

Expiration Date: 5/04/12018