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

Patent metadata

Field	Value
Publication number	US-2017076943-A1
Application number	US-201515125391-A
Country	US
Kind code	A1
Filing date	Mar 9, 2015
Priority date	Mar 14, 2014
Publication date	Mar 16, 2017
Grant date	—

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 and gallium as oxides, contains nitrogen, and does not contain zinc. The gallium content in terms of the atomic ratio Ga/(In+Ga) is between 0.20 and 0.60, inclusive, and substantially no GaN phase is included. Furthermore, the sintered oxide preferably has no Ga 2 O 3 phase. An amorphous oxide semiconductor thin film formed using this oxide sintered body as a sputtering target yields a carrier density of 3.0×10 18 cm −3 or less, and a carrier mobility of 10 cm 2 V −1 sec −1 or more.

First claim

1 . An oxide sintered body comprising indium and gallium as oxides, wherein
a gallium content is 0.20 or more and 0.60 or less in terms of Ga/(In+Ga) atomic ratio, the oxide sintered body contains nitrogen but does not contain zinc, and the oxide sintered body does not substantially include a GaN phase having a wurtzite-type structure.

2 . The oxide sintered body according to claim 1 , wherein the gallium content is 0.20 or more and 0.35 or less in terms of Ga/(In+Ga) atomic ratio.

3 . The oxide sintered body according to claim 1 , wherein a density of nitrogen is 1×10 19 atoms/cm 3 or more.

4 . The oxide sintered body according to claim 1 , wherein the oxide sintered body is composed of
an In 2 O 3 phase having a bixbyite-type structure, and a GaInO 3 phase having a β-Ga 2 O 3 -type structure as a formed phase other than the In 2 O 3 phase, or a GaInO 3 phase having a β-Ga 2 O 3 -type structure and a (Ga, In) 2 O 3 phase as a formed phase other than the In 2 O 3 phase.

5 . The oxide sintered body according to claim 4 , wherein an X-ray diffraction peak intensity ratio of a GaInO 3 phase having a β-Ga 2 O 3 -type structure defined by formula 1 below is in a range of 30% or more and 98% or less.
100×I[GaInO 3 phase(111)]/{I[In 2 O 3 phase(400)]+I[GaInO 3 phase(111)]}[%]  Formula 1

6 . The oxide sintered body according to claim 1 , wherein the oxide sintered body does not include a Ga 2 O 3 phase having a β-Ga 2 O 3 -type structure.

7 . The oxide sintered body according to claim 1 , wherein the oxide sintered body is sintered by ordinary-pressure sintering in an atmosphere having a volume fraction of oxygen over 20%.

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

9 . An amorphous oxide semiconductor thin film obtained by film deposition on a substrate by using the sputtering target according to claim 8 by sputtering, followed by heating.

10 . An amorphous oxide semiconductor thin film comprising:
indium and gallium as oxides; and nitrogen; but not comprising zinc, wherein
a gallium content is 0.20 or more and 0.60 or less in terms of Ga/(In+Ga) atomic ratio,
a density of nitrogen is 1×10 18 atoms/cm 3 or more, and
a carrier mobility is 10 cm 2 V −1 sec −1 or more.

11 . The amorphous oxide semiconductor thin film according to claim 10 , wherein the gallium content is 0.20 or more and 0.35 or less in terms of Ga/(In+Ga) atomic ratio.

12 . The amorphous oxide semiconductor thin film according to claim 9 , wherein a carrier density is 3×10 18 cm −3 or less.

13 . The amorphous oxide semiconductor thin film according to claim 9 , wherein a carrier mobility is 20 cm 2 V −1 sec −1 or more.

14 . The amorphous oxide semiconductor thin film according to claim 10 , wherein a carrier density is 3×10 18 cm −3 or less.

15 . The amorphous oxide semiconductor thin film according to claim 10 , wherein a carrier mobility is 20 cm 2 V −1 sec −1 or more.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Nakayama Tokuyuki
• Nishimura Eiichiro
• Iwara Masashi

Classifications

• H10P14/3802

  Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title

• H10P14/22

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

• H10P14/3434 Primary

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

• C04B35/62218

  obtaining ceramic films, e.g. by using temporary supports · CPC title