Method for manufacturing semiconductor device

• US 9,202,877 B2
• Filed: 02/07/2013
• Issued: 12/01/2015
• Est. Priority Date: 04/23/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): STEVENSON, ANDRE C
• Application Number:
  US13/761,498
• Publication Number:
  US 20130146870A1
• Time in Patent Office: 1,027 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/383 using diffusion into or out of a solid from or into a gaseous phase
• CPC Class Codes: H01L 21/477 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/38 - H01L21/449 and H01L21/461 - H01L21/475 take precedence
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/263 Amorphous materials
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

One object of one embodiment of the present invention is to provide a highly reliable semiconductor device including an oxide semiconductor, which has stable electrical characteristics. In a method for manufacturing a semiconductor device, a first insulating film is formed; source and drain electrodes and an oxide semiconductor film electrically connected to the source and drain electrodes are formed over the first insulating film; heat treatment is performed on the oxide semiconductor film so that a hydrogen atom in the oxide semiconductor film is removed; oxygen doping treatment is performed on the oxide semiconductor film, so that an oxygen atom is supplied into the oxide semiconductor film; a second insulating film is formed over the oxide semiconductor film; and a gate electrode is formed over the second insulating film so as to overlap with the oxide semiconductor film.

Claims

1. A semiconductor device comprising:

a metal oxide layer;

an oxide semiconductor layer comprising a channel formation region on and in contact with a top surface of the metal oxide layer, the oxide semiconductor layer comprising oxygen, indium, zinc and gallium; and

a gate electrode adjacent to the oxide semiconductor layer,

wherein the metal oxide layer comprises oxygen, indium, zinc and gallium, and

wherein the metal oxide layer reduces an amount of oxygen vacancy which is associated with a bond between indium and oxygen.

2. The semiconductor device according to claim 1, wherein the metal oxide layer is insulating.

3. The semiconductor device according to claim 1, wherein the gate electrode is located over the oxide semiconductor layer.

4. The semiconductor device according to claim 1, wherein at least part of the metal oxide layer comprises oxygen at a concentration higher than a stoichiometric ratio in order to reduce an amount of oxygen vacancy which is associated with a bond between indium and oxygen.

5. The semiconductor device according to claim 1, wherein at least part of the oxide semiconductor layer comprises oxygen at a concentration higher than a stoichiometric ratio in order to reduce an amount of oxygen vacancy which is associated with a bond between indium and oxygen.

6. The semiconductor device according to claim 1, wherein the metal oxide layer reduces an amount of oxygen vacancy in the oxide semiconductor layer, the oxygen vacancy being associated with a bond between indium and oxygen.

7. The semiconductor device according to claim 1, further comprising:

a source electrode electrically connected to the oxide semiconductor layer; and

a drain electrode electrically connected to the oxide semiconductor layer.

8. The semiconductor device according to claim 1, wherein a bandgap of the metal oxide layer is larger than a bandgap of the oxide semiconductor layer.