Oxide semiconductor

• US 9,391,146 B2
• Filed: 04/02/2015
• Issued: 07/12/2016
• 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:
  US14/677,131
• Publication Number:
  US 20150214309A1
• Time in Patent Office: 467 Days
• Field of Search: None
• US Class Current: 1/1
• 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, gallium and zinc,

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,

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.

2. The oxide semiconductor according to claim 1,

wherein the plurality of crystals is InGaZnO₄ crystals.

3. 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.

4. The oxide semiconductor according to claim 3,

wherein the plurality of spots is circularly arranged.

5. An oxide semiconductor comprising:

indium, gallium and zinc,

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, and

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

6. The oxide semiconductor according to claim 5,

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