Metal oxide film and method for forming metal oxide film

• US 10,461,099 B2
• Filed: 01/25/2018
• Issued: 10/29/2019
• Est. Priority Date: 11/08/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takahashi, Masahiro, Hirohashi, Takuya, Tsubuku, Masashi, Ishihara, Noritaka, Oota, Masashi
• Primary Examiner(s): Kebede, Brook
• Application Number:
  US15/879,506
• Publication Number:
  US 20180151596A1
• Time in Patent Office: 642 Days
• Field of Search: 257 43
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: G01N 23/207 Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 Oxides
• 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 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• 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 29/04 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 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nmφ and less than or equal to 10 nmφ.

Claims

1. A method for manufacturing a metal oxide film comprising:

forming the metal oxide film by a sputtering method using a sputtering target comprising a polycrystalline oxide in an atmosphere where oxygen partial pressure is greater than or equal to 33%,

wherein the sputtering target comprises indium, gallium and zinc,

wherein the metal oxide film comprises a plurality of crystal parts when the metal oxide film is formed,

wherein a size of one of the plurality of crystal parts is less than or equal to 10 nm, and

wherein a crystal peak is not observable in an XRD spectrum with respect to the metal oxide film.

2. The method for manufacturing a metal oxide film according to claim 1,

wherein the size of the one of the plurality of crystal parts is less than or equal to 5 nm.

3. The method for manufacturing a metal oxide film according to claim 1,

wherein the XRD spectrum is measured by an out-of-plane method.

4. The method for manufacturing a metal oxide film according to claim 1,

wherein the metal oxide film is formed without heating a substrate on which the metal oxide film is formed.

5. The method for manufacturing a metal oxide film according to claim 1, further comprising,

performing a first heat treatment in an atmosphere comprising nitrogen, and

performing a second heat treatment in an atmosphere comprising nitrogen and oxygen.

6. A method for manufacturing a metal oxide film comprising:

forming the metal oxide film by a sputtering method using a sputtering target comprising a polycrystalline oxide in an atmosphere where oxygen partial pressure is greater than or equal to 33%,

wherein the sputtering target comprises indium, gallium and zinc,

wherein the metal oxide film comprises a crystal part when the metal oxide film is formed,

wherein a size of the crystal part is less than or equal to 10 nm,

wherein a crystal peak is not observable in an XRD spectrum with respect to the metal oxide film, and

wherein a plurality of circumferentially distributed spots are observable in a measurement area greater than or equal to an area with a diameter of 5 nmφ and

less than or equal to an area with a diameter of 10 nmφ

in a nanobeam electron diffraction pattern of a cross-section of the metal oxide film.

7. The method for manufacturing a metal oxide film according to claim 6,

wherein there is no difference between the first plurality of circumferentially distributed spots and a second plurality of circumferentially distributed spots which are observable in a nanobeam electron diffraction of a cross-section in which a measurement area is 5 nmϕ

or more and 10 nmϕ

or less with respect to the same metal oxide film after being irradiated with an electron beam whose beam diameter is converged to about 1 nmϕ

for one minute.

8. The method for manufacturing a metal oxide film according to claim 7,

wherein an acceleration voltage for the electron beam is 200 kV.

9. The method for manufacturing a metal oxide film according to claim 6,

wherein the size of the crystal part is less than or equal to 5 nm.

10. The method for manufacturing a metal oxide film according to claim 6,

wherein the XRD spectrum is measured by an out-of-plane method.

11. The method for manufacturing a metal oxide film according to claim 6,

wherein the metal oxide film is formed without heating a substrate on which the metal oxide film is formed.

12. The method for manufacturing a metal oxide film according to claim 6, further comprising,

performing a first heat treatment in an atmosphere comprising nitrogen, and

performing a second heat treatment in an atmosphere comprising nitrogen and oxygen.

13. A method for manufacturing a metal oxide film comprising:

forming the metal oxide film by a sputtering method using a sputtering target comprising a polycrystalline oxide in an atmosphere where oxygen partial pressure is greater than or equal to 33%,

wherein the sputtering target comprises indium, gallium and zinc,

wherein the metal oxide film comprises a crystal part when the metal oxide film is formed,

wherein a size of the crystal part is less than or equal to 10 nm,

wherein a crystal peak is not observable in an XRD spectrum with respect to the metal oxide film,

wherein a plurality of circumferentially distributed spots are observable in a measurement area greater than or equal to an area with a diameter of 5 nmφ and

less than or equal to an area with a diameter of 10 nmφ

in a nanobeam electron diffraction pattern of a cross-section of the metal oxide film, and

wherein a halo pattern is observable in a selected-area electron diffraction pattern of a plane of the metal oxide film.

14. The method for manufacturing a metal oxide film according to claim 13,

wherein there is no difference between the first plurality of circumferentially distributed spots and a second plurality of circumferentially distributed spots which are observable in a nanobeam electron diffraction of a cross-section in which a measurement area is 5 nmϕ

or more and 10 nmϕ

or less with respect to the same metal oxide film after being irradiated with an electron beam whose beam diameter is converged to about 1 nmϕ

for one minute.

15. The method for manufacturing a metal oxide film according to claim 14,

wherein an acceleration voltage for the electron beam is 200 kV.

16. The method for manufacturing a metal oxide film according to claim 13,

wherein the size of the crystal part is less than or equal to 5 nm.

17. The method for manufacturing a metal oxide film according to claim 13,

wherein the XRD spectrum is measured by an out-of-plane method.

18. The method for manufacturing a metal oxide film according to claim 13,

wherein the metal oxide film is formed without heating a substrate on which the metal oxide film is formed.

19. The method for manufacturing a metal oxide film according to claim 13, further comprising,

performing a first heat treatment in an atmosphere comprising nitrogen, and

performing a second heat treatment in an atmosphere comprising nitrogen and oxygen.