OXIDE SINTERED BODY, SPUTTERING TARGET, AND OXIDE SEMICONDUCTOR THIN FILM OBTAINED USING SPUTTERING TARGET

• US 20170076943A1
• Filed: 03/09/2015
• Published: 03/16/2017
• Est. Priority Date: 03/14/2014
• Status: Abandoned Application

• Current Assignee: Sumitomo Metal Mining Company Limited
• Original Assignee: Sumitomo Metal Mining Company Limited
• Inventors: NAKAYAMA, Tokuyuki, NISHIMURA, Eiichiro, IWARA, Masashi
• Application Number:
  US15/125,391
• Publication Number:
  US 20170076943A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6565 Cooling rate
• CPC Class Codes: C04B 2235/6583 Oxygen containing atmosphere, e.g. with changing oxygen pressures
• CPC Class Codes: C04B 2235/6585 at an oxygen percentage above that of air
• CPC Class Codes: C04B 2235/6586 Processes characterised by the flow of gas
• CPC Class Codes: C04B 2235/72 Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/722 Nitrogen content
• CPC Class Codes: C04B 2235/76 Crystal structural characteristics, e.g. symmetry
• CPC Class Codes: C04B 2235/762 Cubic symmetry, e.g. beta-SiC
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/81 Materials characterised by the absence of phases other than the main phase, i.e. single phase materials
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C04B 35/62218 obtaining ceramic films, e.g. by using temporary supports
• CPC Class Codes: C04B 35/62695 Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/3407 : Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: C23C 14/3414 : Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01J 37/3426 : Material
• CPC Class Codes: H01L 21/02422 : Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02565 : Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 : Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/02667 : Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• 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 29/221 : including two or more compounds , e.g. alloys H01L29/2206 takes precedence
• 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 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 Ga₂O₃ phase. An amorphous oxide semiconductor thin film formed using this oxide sintered body as a sputtering target yields a carrier density of 3.0×10¹⁸ cm⁻³ or less, and a carrier mobility of 10 cm² V⁻¹ sec⁻¹ or more.

Claims

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×

10¹⁹ atoms/cm³ or more.

4. The oxide sintered body according to claim 1, wherein the oxide sintered body is composed of

an In₂O₃ phase having a bixbyite-type structure,

and a GaInO₃ phase having a β

-Ga₂O₃-type structure as a formed phase other than the In₂O₃ phase, or a GaInO₃ phase having a β

-Ga₂O₃-type structure and a (Ga, In)₂O₃ phase as a formed phase other than the In₂O₃ phase.

5. The oxide sintered body according to claim 4, wherein an X-ray diffraction peak intensity ratio of a GaInO₃ phase having a β

-Ga₂O₃-type structure defined by formula 1 below is in a range of 30% or more and 98% or less.

100×

I[GaInO₃ phase(111)]/{I[In₂O₃ phase(400)]+I[GaInO₃ phase(111)]}[%] 

 

Formula 1

6. The oxide sintered body according to claim 1, wherein the oxide sintered body does not include a Ga₂O₃ phase having a β

-Ga₂O₃-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.

12. The amorphous oxide semiconductor thin film according to claim 9, wherein a carrier density is 3×

10¹⁸ cm<sup>−

3</sup> or less.

13. The amorphous oxide semiconductor thin film according to claim 9, wherein a carrier mobility is 20 cm² V⁻

1 sec<sup>−

1</sup> or more.

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×

10¹⁸ atoms/cm³ or more, and

a carrier mobility is 10 cm² V<sup>−

1</sup> sec<sup>−

1</sup> 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.

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

10¹⁸ cm<sup>−

3</sup> or less.

15. The amorphous oxide semiconductor thin film according to claim 10, wherein a carrier mobility is 20 cm² V⁻

1 sec<sup>−

1</sup> or more.