Oxide semiconductor

• US 9,771,272 B2
• Filed: 06/13/2016
• Issued: 09/26/2017
• Est. Priority Date: 03/19/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Takahashi, Masahiro, Kimizuka, Noboru
• Primary Examiner(s): CHEN, JACK S J
• Application Number:
  US15/180,695
• Publication Number:
  US 20160297686A1
• Time in Patent Office: 470 Days
• Field of Search: None
• CPC Class Codes: C01G 15/00 Compounds of gallium, indium or thallium
• CPC Class Codes: C01G 15/006 Compounds containing, besides gallium, indium, or thallium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/60 Compounds characterised by their crystallite size
• CPC Class Codes: C01P 2002/70 defined by measured X-ray, neutron or electron diffraction data
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/54 Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C01P 2006/40 Electric properties
• 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 29/22 including, apart from doping materials or other impurities, only AIIBVI compounds
• 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 29/26 including, apart from doping materials or other impurities, elements provided for in two or more of the groups H01L29/16, H01L29/18, H01L29/20, H01L29/22, H01L29/24 , e.g. alloys
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

To provide an oxide semiconductor with a novel structure. Such an oxide semiconductor is composed of an aggregation of a plurality of InGaZnO₄ crystals each of which is larger than or equal to 1 nm and smaller than or equal to 3 nm, and in the oxide semiconductor, the plurality of InGaZnO₄ crystals have no orientation. Alternatively, such an oxide semiconductor is such that a diffraction pattern like a halo pattern is observed by electron diffraction measurement performed by using an electron beam with a probe diameter larger than or equal to 300 nm, and that a diffraction pattern having a plurality of spots arranged circularly is observed by electron diffraction measurement performed by using an electron beam with a probe diameter larger than or equal to 1 nm and smaller than or equal to 30 nm.

Claims

1. An oxide semiconductor comprising:

an aggregation of a plurality of crystals,

wherein the plurality of crystals includes indium,

wherein each of the plurality of crystals has a size larger than or equal to 1 nm and smaller than or equal to 3 nm, and

wherein half widths at half maximum of a diffraction peak of the oxide semiconductor is 0.4 nm<sup>−

1</sup> to 0.6 nm<sup>−

1</sup>.

2. The oxide semiconductor according to claim 1,

wherein the plurality of crystals has no orientation, and

wherein a boundary between the plurality of crystals is not observed in a TEM image of the oxide semiconductor.

3. The oxide semiconductor according to claim 1,

wherein the plurality of crystals further includes gallium and zinc.

4. The oxide semiconductor according to claim 3,

wherein the plurality of crystals is InGaZnO4 crystals.

5. The oxide semiconductor according to claim 1,

wherein a diffraction pattern having a plurality of spots is observed when an electron diffraction measurement is performed on the oxide semiconductor by using an electron beam with a probe diameter larger than or equal to 1 nm and smaller than or equal to 30 nm, and

wherein a diffraction pattern with no spot is observed when an electron diffraction measurement is performed on the oxide semiconductor by using an electron beam with a probe diameter larger than or equal to 300 nm.

6. The oxide semiconductor according to claim 5,

wherein the plurality of spots is circularly arranged.

7. An oxide semiconductor comprising:

indium,

wherein a diffraction pattern having a plurality of spots circularly arranged is observed when an electron diffraction measurement is performed on the oxide semiconductor by using an electron beam with a probe diameter larger than or equal to 1 nm and smaller than or equal to 30 nm,

wherein a diffraction pattern with no spot is observed when an electron diffraction measurement is performed on the oxide semiconductor by using an electron beam with a probe diameter larger than or equal to 300 nm,

wherein a grain boundary is not observed in a TEM image of the oxide semiconductor, and

wherein half widths at half maximum of a diffraction peak of the oxide semiconductor is 0.4 nm<sup>−

1</sup> to 0.6 nm<sup>−

1</sup>.

8. The oxide semiconductor according to claim 7, further comprising gallium and zinc.

9. The oxide semiconductor according to claim 8,

wherein the plurality of spots circularly arranged is derived from InGaZnO₄ crystals having no orientation.