Manufacturing method of oxide semiconductor device

• US 8,802,493 B2
• Filed: 09/06/2012
• Issued: 08/12/2014
• Est. Priority Date: 09/13/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koezuka, Junichi, Ohno, Shinji, Sato, Yuichi, Tezuka, Sachiaki, Yokoi, Tomokazu, Shino, Yusuke
• Primary Examiner(s): YUSHIN, NIKOLAY K
• Application Number:
  US13/604,937
• Publication Number:
  US 20130062600A1
• Time in Patent Office: 705 Days
• Field of Search: 438/104, 438/474, 438/513, 438/798
• US Class Current: 438/104
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/242 AIBVI or AIBVII compounds, e.g. Cu2O, Cu I H01L29/247 takes precedence
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• 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: H10B 12/05 Making the transistor
• CPC Class Codes: H10B 41/70 the floating gate being an electrode shared by two or more components

Abstract

The contact resistance between an oxide semiconductor film and a metal film is reduced. A transistor that uses an oxide semiconductor film and has excellent on-state characteristics is provided. A semiconductor device capable of high-speed operation is provided. In a transistor that uses an oxide semiconductor film, the oxide semiconductor film is subjected to nitrogen plasma treatment. Thus, part of oxygen included in the oxide semiconductor film is replaced with nitrogen, so that an oxynitride region is formed. A metal film is formed in contact with the oxynitride region. The oxynitride region has lower resistance than the other region of the oxide semiconductor film. In addition, the oxynitride region is unlikely to form high-resistance metal oxide at the interface with the contacting metal film.

Claims

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

forming an oxide semiconductor film on an insulating surface;

forming a gate insulating film over the oxide semiconductor film;

forming a gate electrode over the gate insulating film;

forming an interlayer insulating film covering the oxide semiconductor film, the gate insulating film, and the gate electrode;

forming an opening in the interlayer insulating film reaching the oxide semiconductor film;

performing nitrogen plasma treatment on the oxide semiconductor film through the opening in the interlayer insulating film; and

forming a metal film in the opening and over the interlayer insulating film.

2. The manufacturing method of the semiconductor device according to claim 1, wherein the nitrogen plasma treatment is microwave discharge nitrogen plasma treatment.

3. The manufacturing method of the semiconductor device according to claim 1, wherein the oxide semiconductor film comprises a crystalline region having a c-axis aligned in a direction perpendicular to a surface of the oxide semiconductor film.

4. The manufacturing method of the semiconductor device according to claim 1, wherein the oxide semiconductor film comprises at least one element selected from In, Ga, Sn, and Zn.

5. The manufacturing method of the semiconductor device according to claim 1, wherein the nitrogen plasma treatment is performed at a temperature of 300°

C. or higher.

6. The manufacturing method of the semiconductor device according to claim 1, further comprising the step of reducing a resistance of part of the oxide semiconductor film to form a low-resistance region after the step of forming the gate electrode.

7. The manufacturing method of the semiconductor device according to claim 6, wherein the low-resistance region comprises at least one kind of element selected from hydrogen, helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon.

8. The manufacturing method of the semiconductor device according to claim 6, wherein a sheet resistance in the low-resistance region is reduced to be 30 kΩ

/sq or less.

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

forming a source electrode and a drain electrode on an insulating surface;

forming an oxide semiconductor film over the source electrode and the drain electrode;

forming a gate insulating film over the oxide semiconductor film;

forming a gate electrode over the gate insulating film;

reducing a resistance of part of the oxide semiconductor film to form a low-resistance region;

forming an interlayer insulating film covering the oxide semiconductor film, the gate insulating film, and the gate electrode;

forming an opening in the interlayer insulating film reaching the oxide semiconductor film;

performing nitrogen plasma treatment on the oxide semiconductor film through the opening in the interlayer insulating film; and

forming a metal film in the opening and over the interlayer insulating film.

10. The manufacturing method of the semiconductor device according to claim 9, wherein the nitrogen plasma treatment is microwave discharge nitrogen plasma treatment.

11. The manufacturing method of the semiconductor device according to claim 9, wherein the oxide semiconductor film comprises a crystalline region having a c-axis aligned in a direction perpendicular to a surface of the oxide semiconductor film.

12. The manufacturing method of the semiconductor device according to claim 9, wherein the oxide semiconductor film comprises at least one element selected from In, Ga, Sn, and Zn.

13. The manufacturing method of the semiconductor device according to claim 9, wherein the low-resistance region comprises at least one kind of element selected from hydrogen, helium, boron, nitrogen, fluorine, neon, aluminum, phosphorus, argon, arsenic, krypton, indium, tin, antimony, and xenon.

14. The manufacturing method of the semiconductor device according to claim 9, wherein a sheet resistance in the low-resistance region is reduced to be 30 kΩ

/sq or less.

15. The manufacturing method of the semiconductor device according to claim 9, wherein the nitrogen plasma treatment is performed at a temperature of 300°

C. or higher.

16. The manufacturing method of the semiconductor device according to claim 9, wherein the source electrode and the drain electrode are formed by planarizing a conductive film on an insulating film with depressions so that the source electrode and the drain electrode are formed in the depressions.