Oxide sintered body, sputtering target, and oxide semiconductor thin film obtained using sputtering target

Patent metadata

Field	Value
Publication number	US-9670578-B2
Application number	US-201515117531-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 27, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

An oxide sintered body which, when made into an oxide semiconductor thin film by sputtering, can achieve low carrier density and high carrier mobility, and a sputtering target using said oxide sintered body are provided. This oxide sintered body contains indium, gallium and zinc as oxides. The gallium content is 0.08 or more and less than 0.20 in terms of Ga/(In+Ga) atomic ratio, and the zinc content is 0.0001 or more and less than 0.08 in terms of Zn/(In+Ga+Zn) atomic ratio. This crystalline oxide semiconductor thin film is formed with the oxide sintered body as a sputtering target, and can achieve a carrier density of 8.0×10 17 cm −3 or less and a carrier mobility of 10 cm 2 /V·s or greater.

First claim

The invention claimed is:

1. An oxide sintered body comprising indium, gallium, and zinc as oxides, wherein
a gallium content is 0.08 or more and less than 0.20 in terms of Ga/(In+Ga) atomic ratio, and
a zinc content is 0.0001 or more and less than 0.08 in terms of Zn/(In+Ga+Zn) atomic ratio,
wherein the oxide sintered body comprises an In 2 O 3 phase having a bixbyite-type structure and a formed phase other than the In 2 O 3 phase, the formed phase being selected from the group consisting of: a GaInO 3 phase having a β-Ga 2 O 3 -type structure; a GaInO 3 phase having a β-Ga 2 O 3 -type structure and a (Ga, In) 2 O 3 phase; a GaInO 3 phase having a β-Ga 2 O 3 -type structure and an In 2 Ga 2 ZnO 7 phase having an Yb 2 Fe 3 O 7 -type structure; a (Ga, In) 2 O 3 phase and an In 2 Ga 2 ZnO 7 phase having an Yb 2 Fe 3 O 7 -type structure; and a GaInO 3 phase having a β-Ga 2 O 3 -type structure, a (Ga, In) 2 O 3 phase, and an In 2 Ga 2 ZnO 7 phase having an Yb 2 Fe 3 O 7 -type structure.

2. The oxide sintered body according to claim 1 , wherein the zinc content is 0.01 or more and 0.05 or less in terms of Zn/(In+Ga+Zn) atomic ratio.

3. The oxide sintered body according to claim 1 , wherein the gallium content is 0.08 or more and 0.15 or less in terms of Ga/(In+Ga) atomic ratio.

4. The oxide sintered body according to claim 1 , wherein the oxide sintered body is substantially free of positive divalent elements other than zinc and positive trivalent to positive hexavalent elements other than indium and gallium.

5. The oxide sintered body according to claim 1 , wherein an X-ray diffraction peak intensity ratio of the In 2 Ga 2 ZnO 7 phase having a Yb 2 Fe 3 O 7 -type structure defined by formula 1 below is in the range of 43% or less:
100 ×I [In 2 Ga 2 ZnO 7 phase (0010)]/{ I [In 2 O 3 phase (400)]+ I [In 2 Ga 2 ZnO 7 phase (0010)]}[%]  Formula 1

(wherein I [In 2 O 3 phase (400)] represents a (400) peak intensity of the In 2 O 3 phase having a bixbyite-type structure, and [In 2 Ga 2 ZnO 7 phase (0010)] represents a (0010) peak intensity of the In 2 Ga 2 ZnO 7 phase having a Yb 2 Fe 3 O 7 -type structure).

6. A sputtering target obtained by machining the oxide sintered body according to claim 1 .

7. A crystalline oxide semiconductor thin film obtained by forming an amorphous film on a substrate by sputtering using the sputtering target according to claim 6 and then crystallizing the amorphous film by heating in an oxidizing atmosphere.

8. The oxide semiconductor thin film according to claim 7 , wherein the oxide semiconductor thin film has a carrier mobility of 10 cm 2 /V·s or more.

9. The oxide semiconductor thin film according to claim 7 , wherein the oxide semiconductor thin film has a carrier mobility of 15 cm 2 /V·s or more.

10. The oxide semiconductor thin film according to claim 7 , wherein the oxide semiconductor thin film has a carrier density of 8.0×10 17 cm −3 or less.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Nakayama Tokuyuki
• Nishimura Eiichiro
• Matsumura Fumihiko
• Iwara Masashi

Classifications

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3426

  Oxides · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title

• C04B2235/3284

  Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof · CPC title

• C04B2235/76

  Crystal structural characteristics, e.g. symmetry · CPC title