Method of manufacturing semiconductor device having oxide semiconductor layer

• US 9,196,713 B2
• Filed: 08/28/2014
• Issued: 11/24/2015
• Est. Priority Date: 09/01/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Akimoto, Kengo
• Primary Examiner(s): Schoenholtz, Joseph
• Application Number:
  US14/471,632
• Publication Number:
  US 20150050774A1
• Time in Patent Office: 453 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02318 post-treatment
• CPC Class Codes: H01L 21/02323 introduction of oxygen
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 29/247 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 29/7869 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
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

An object is to provide favorable interface characteristics of a thin film transistor including an oxide semiconductor layer without mixing of an impurity such as moisture. Another object is to provide a semiconductor device including a thin film transistor having excellent electric characteristics and high reliability, and a method by which a semiconductor device can be manufactured with high productivity. A main point is to perform oxygen radical treatment on a surface of a gate insulating layer. Accordingly, there is a peak of the oxygen concentration at an interface between the gate insulating layer and a semiconductor layer, and the oxygen concentration of the gate insulating layer has a concentration gradient. The oxygen concentration is increased toward the interface between the gate insulating layer and the semiconductor layer.

Claims

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

forming an insulating layer comprising an oxide over a substrate;

adding oxygen to the insulating layer to increase an oxygen concentration in the insulating layer;

forming an oxide semiconductor layer over the insulating layer after adding oxygen to the insulating layer; and

heating the oxide semiconductor layer at a temperature of 200°

C. or higher.

2. The method according to claim 1, wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.

3. The method according to claim 1, wherein the step of heating is performed at a temperature of 600°

C. or lower.

4. The method according to claim 1, further comprising the step of:

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer.

5. The method according to claim 1, wherein the oxide semiconductor layer comprises In, Ga and Zn.

6. The method according to claim 1, wherein the oxide semiconductor layer comprises In and Zn.

14. The method according to claim 1, wherein the step of heating is performed at a temperature of 600°

C. or lower.

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

forming a gate electrode layer over a substrate;

forming a gate insulating layer comprising an oxide over the gate electrode layer;

adding oxygen to the gate insulating layer to increase an oxygen concentration in the gate insulating layer;

forming an oxide semiconductor layer on the gate insulating layer after adding oxygen to the gate insulating layer; and

heating the oxide semiconductor layer at a temperature of 200°

C. or higher.

8. The method according to claim 7, wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.

9. The method according to claim 7, wherein the step of heating is performed at a temperature of 600°

C. or lower.

10. The method according to claim 7, wherein the oxide semiconductor layer comprises In, Ga and Zn.

11. The method according to claim 7, wherein the oxide semiconductor layer comprises In and Zn.

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

forming an insulating layer comprising an oxide over a substrate;

adding oxygen to the insulating layer to increase an oxygen concentration in the insulating layer;

forming an oxide semiconductor layer over the insulating layer after adding oxygen to the insulating layer;

forming an insulating film over the oxide semiconductor layer; and

heating the oxide semiconductor layer at a temperature of 200°

C. or higher.

13. The method according to claim 12, wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.

15. The method according to claim 12, further comprising the step of:

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer.

16. The method according to claim 12, wherein the oxide semiconductor layer comprises In, Ga and Zn.

17. The method according to claim 12, wherein the oxide semiconductor layer comprises In and Zn.