Method for manufacturing semiconductor device

• US 9,831,101 B2
• Filed: 05/09/2016
• Issued: 11/28/2017
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sasaki, Toshinari, Sakata, Junichiro, Ohara, Hiroki, Yamazaki, Shunpei
• Primary Examiner(s): BACHNER, ROBERT G
• Application Number:
  US15/149,464
• Publication Number:
  US 20160254167A1
• Time in Patent Office: 568 Days
• Field of Search: None
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/383 using diffusion into or out of a solid from or into a gaseous phase
• CPC Class Codes: H01L 21/46 Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/428 manufacture of electrodes thereon H01L21/44
• 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 29/66969 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith.

Claims

1. A method for manufacturing a semiconductor device comprising the steps of:

forming an oxide semiconductor layer of which a carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup>;

cooling the oxide semiconductor layer under an atmosphere containing oxygen; and

forming an insulating layer in contact with a part of the oxide semiconductor layer,

wherein the part of the oxide semiconductor layer serves as a channel formation region.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer of which the carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup> is formed by heating under an atmosphere containing nitrogen.

3. The method for manufacturing a semiconductor device according to claim 2, wherein the heating is performed at a temperature higher than or equal to 400°

C.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer of which the carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup> is formed by heating under reduced pressure.

5. The method for manufacturing a semiconductor device according to claim 4, wherein the heating is performed at a temperature higher than or equal to 400°

C.

6. The method for manufacturing a semiconductor device according to claim 1, wherein a carrier concentration of the part of the oxide semiconductor layer is lower than or equal to 1×

10¹⁴ cm<sup>−

3</sup>.

7. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer further comprises gallium and zinc.

8. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer further comprises tin and zinc.

9. A method for manufacturing a semiconductor device comprising the steps of:

forming an oxide semiconductor layer of which a carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup>;

cooling the oxide semiconductor layer under an atmosphere containing oxygen;

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

forming an insulating layer in contact with a part of the oxide semiconductor layer, the source electrode, and the drain electrode,

wherein the part of the oxide semiconductor layer serves as a channel formation region.

10. The method for manufacturing a semiconductor device according to claim 9, wherein the oxide semiconductor layer of which the carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup> is formed by heating under an atmosphere containing nitrogen.

11. The method for manufacturing a semiconductor device according to claim 10, wherein the heating is performed at a temperature higher than or equal to 400°

C.

12. The method for manufacturing a semiconductor device according to claim 9, wherein the oxide semiconductor layer of which the carrier concentration is higher than or equal to 1×

10¹⁸ cm<sup>−

3</sup> is formed by heating under reduced pressure.

13. The method for manufacturing a semiconductor device according to claim 12, wherein the heating is performed at a temperature higher than or equal to 400°

C.

14. The method for manufacturing a semiconductor device according to claim 9, wherein a carrier concentration of the part of the oxide semiconductor layer is lower than or equal to 1×

10¹⁴ cm<sup>−

3</sup>.

15. The method for manufacturing a semiconductor device according to claim 9, wherein the oxide semiconductor layer further comprises gallium and zinc.

16. The method for manufacturing a semiconductor device according to claim 9, wherein the oxide semiconductor layer further comprises tin and zinc.