Epitaxial growth of ZnO with controlled atmosphere
AssigneeStanley Electric Co., Ltd.
InventorsHiroyuki Kato, Michihiro Sano
Life of this patent
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Abstract
A ZnO crystal growth method has the steps of (a) preparing a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane; (b) supplying Zn and O above the surface of the substrate by alternately repeating a Zn-rich condition period and an O-rich condition period; and (c) supplying conductivity type determining impurities above the surface of the substrate while Zn and O are supplied at the step (b).
Claims23
A ZnO crystal growth method comprising steps of:
- (a) loading a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane into a growth chamber;
- and
- (b) epitaxially and two-dimensionally growing an impurities-doped ZnO layer, by supplying Zn and O above the surface of said substrate in said growth chamber by alternately repeating a Zn-rich condition period, which grows ZnO, and an O-rich condition period, which grows ZnO, while supplying conductivity type determining impurities above the surface of said substrate.
A ZnO crystal growth method comprising steps of:
- (a) loading a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane into a growth chamber;
- and
- (b) epitaxially and two-dimensionally growing an impurities-doped ZnO layer, by supplying Zn and O above the surface of said substrate in said growth chamber by alternately repeating a period in which a ratio of an O supply amount to a Zn supply amount takes a first value, which grows ZnO, and a period in which the ratio takes a second value different from said first value, which grows ZnO, while supplying conductivity type determining impurities above the surface of said substrate.
A ZnO crystal of a p-type conductivity exposing a Zn polarity plane on a surface thereof and doped with N at a concentration of 1×1019 cm−3 or higher, wherein a diffraction image of said surface observed through reflection high-energy electron diffraction shows a streak pattern.
A ZnO crystal of a p-type conductivity exposing a Zn polarity plane on a surface thereof and doped with N at a concentration of 1×1019 cm−3 or higher, wherein a an RMS value of a roughness of said surface measured with an atomic force microscope is 2 nm or smaller.
A ZnO crystal of an n-type conductivity exposing a Zn polarity plane on a surface thereof, doped with Ga at a concentration of 1×1018 cm−3 or higher, and having an electron concentration of 1018 cm−3 or higher, wherein a diffraction image of said surface observed through reflection high-energy electron diffraction shows a streak pattern.
A ZnO crystal of an n-type conductivity exposing a Zn polarity plane on a surface thereof, doped with Ga at a concentration of 1×1018 cm−3 or higher, and having an electron concentration of 1018 cm−3 or higher, wherein a an RMS value of a roughness of said surface measured with an atomic force microscope is 2 nm or smaller.
A light emitting device manufacture method comprising steps of:
- (a) preparing a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane;
- (b) growing an n-type ZnO layer doped with n-type impurities above said surface of said substrate;
- (c) epitaxially and two-dimensionally growing a p-type ZnO layer doped with p-type impurities above said surface of said substrate;
- (d) forming an active layer between said n-type ZnO layer and said p-type ZnO layer;
- (e) forming an n-side electrode for applying voltage to said n-type ZnO layer;
- and
- (f) forming a p-side electrode for applying voltage to said p-type ZnO layer,
- wherein said step (c) includes steps of:
- (c-1) supplying Zn and O by alternately repeating a Zn-rich condition period, which grows ZnO, and an O-rich condition period, which grows ZnO;
- and
- (c-2) supplying at least one of N, P and As while Zn and O are supplied at said step (c-1).
A light emitting device manufacture method comprising steps of:
- (a) preparing a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane;
- (b) growing an n-type ZnO layer doped with n-type impurities above said surface of said substrate;
- (c) epitaxially and two-dimensionally growing a p-type ZnO layer doped with p-type impurities above said surface of said substrate;
- (d) forming an active layer between said n-type ZnO layer and said p-type ZnO layer;
- (e) forming an n-side electrode for applying voltage to said n-type ZnO layer;
- and
- (f) forming a p-side electrode for applying voltage to said p-type ZnO layer,
- wherein said step (c) includes steps of:
- (c-1) supplying Zn and O by alternately repeating a period while a ratio of an O supply amount to a Zn supply amount takes a first value, which grows ZnO, and a period in which the ratio takes a second value different from said first value, which grows ZnO;
- and
- (c-2) supplying at least one of N, P and As while Zn and O are supplied at said step (c-1).
A ZnO crystal growth method comprising steps of:
- (a) loading a substrate having a surface capable of growing ZnO crystal exposing a Zn polarity plane into a growth chamber;
- and
- (b) epitaxially and two-dimensionally growing an impurities-doped p-type ZnO layer, by supplying Zn and O above the surface of said substrate in said growth chamber by alternately repeating a Zn-rich condition period, which grows ZnO, and an O-rich condition period, which grows ZnO, while supplying p-type impurities above the surface of said substrate so that the two-dimensionally grown impurities-doped p-type ZnO layer has a concentration of the p-type impurities within a range between about 5×1018 cm−3 and about 6×1020 cm−3.
Dependencies are inferred from the claim text.