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Semiconductor light emitting device with an active layer made of semiconductor having uniaxial anisotropy

Assignee: Fujitsu Ltd
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Filing: 1997-02-24
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Granted: 2000-06-06
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Expires: 2017-02-24
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Abstract

Abstract A semiconductor light emitting device includes a second semiconductor layer, an active layer, a third semiconductor layer and a pair of electrodes. The second semiconductor layer is formed directly on the principal pane of a substrate or via a first semiconductor layer. The active layer is formed on the second semiconductor layer and has an energy band gap which is smaller than the energy band gap of the second semiconductor layer. The active layer is made of a semiconductor having an uniaxial anisotropy. The third semiconductor layer is formed on the active layer and has the energy band gap which is larger than the energy band gap of the active layer. The pair of electrodes supplies current to the second semiconductor layer, the active layer, and the third semiconductor layer in the film thickness direction. The film thickness direction of at least the active layer is different from the axis of the uniaxial anisotropy.

Inventors

  • 👤 Kazuhiko Horino
  • 👤 Kay Domen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 14:42
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/822; H10H20/824; H10H20/825; H10H20/817; H10H29/00; H10H29/10; H10H29/14; H10H29/142; H10H20/819; H10H20/821; H10H20/85; H10H20/857; H10W; H10W72/00; H10W72/071; H10W72/075; H10W72/07551; H10W72/07554; H10W72/50; H10W72/541; H10W72/547; H10W72/851; H10W72/874; H10W72/884; H10W74/00

Claims Analysis

Total Claims: 48
Claim 1
Independent Claim 168 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and, a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction, wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy, and light is emitted vertically relative to said principal plane.
Claim 2
Dependent Claim 168 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and, a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction, wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy, and light is emitted vertically relative to said principal plane.
Claim 3
Dependent Claim 18 words
A semiconductor light emitting device according to claim 1, wherein said semiconductor of active layer is wurtzite nitride.
Claim 4
Dependent Claim 53 words
A semiconductor light emitting device according to claim 1, wherein said substrate is made of GaN, AlN or SiC, and said principal a plane is {1 100} plane, {1120} plane or a plane of said substrate inclined at -5 to +5 degree with said a {1 100} plane or said {11 20} plane.
Claim 5
Dependent Claim 43 words
A semiconductor light emitting device according to claim 1, wherein said crystal substrate is formed of a LiAlO 2 substrate, said principal plane is either a {100} plane or face inclined at an angle of -5 to +5 degree with said {100} face.
Claim 6
Dependent Claim 27 words
A semiconductor light emitting device according to claim 1, wherein said active layer is formed of Al x Ga l-x-y In y N (where 0≦x≦1 and 0≦y≦1).
Claim 7
Dependent Claim 58 words
A semiconductor light emitting device according to claim 1, furthermore comprising a mirror layer is formed beneath said second semiconductor layer or on said third semiconductor layer, and a resonator is formed using said mirror layer as one end surface in a film thickness direction of said active layer, said second semiconductor layer, and said third semiconductor layer.
Claim 8
Dependent Claim 26 words
A semiconductor light emitting device according to claim 6, wherein a resonance wavelength of said resonator is a wavelength which renders photo luminescence light intensity maximum.
Claim 9
Dependent Claim 60 words
A semiconductor light emitting device according to claim 6, wherein said active layer is formed of any of a multiple quantum well layer having a multi-layered structure of a first layer made of GaN or InGaN and a second layer made of AlGaInN or GaN or InGaN, a GaN single layer, an InGaN single layer, and an AlGaInN single layer.
Claim 10
Dependent Claim 39 words
A semiconductor light emitting device according to claim 6, wherein said principal plane of said crystal substrate is a {11 20} plane or a {1100} plane of an SiC substrate, or a {1 102} plane of a sapphire substrate.
Claim 11
Dependent Claim 163 words
A semiconductor light emitting device comprising: a first barrier layer formed of a first conductive type AlGaN which is deposited on an SiC substrate using a {1120} plane as a principal plane; an active layer formed of a multiple quantum well layer including an InGaN layer, a multiple quantum well layer including an AlGaN layer, a GaN single layer, and an InGaN single layer, which is deposited on said first barrier layer, said active layer having a c axis exhibiting anisotropy along its face of a light emitted surface; a second barrier layer formed of a second conductive type AlGaN which is deposited on said active layer; an optical resonator formed in a film thickness direction, said optical resonator being formed by using a reflection mirror which is made of a multi-layered film provided on said second barrier layer as a first reflection surface and having a second reflection surface beneath said first barrier layer; and a first electrode and a second electrode.
Claim 12
Dependent Claim 163 words
A semiconductor light emitting device comprising: a first barrier layer formed of a first conductive type AlGaN which is deposited on an SiC substrate using a {1120} plane as a principal plane; an active layer formed of a multiple quantum well layer including an InGaN layer, a multiple quantum well layer including an AlGaN layer, a GaN single layer, and an InGaN single layer, which is deposited on said first barrier layer, said active layer having a c axis exhibiting anisotropy along its face of a light emitted surface; a second barrier layer formed of a second conductive type AlGaN which is deposited on said active layer; an optical resonator formed in a film thickness direction, said optical resonator being formed by using a reflection mirror which is made of a multi-layered film provided on said second barrier layer as a first reflection surface and having a second reflection surface beneath said first barrier layer; and a first electrode and a second electrode.
Claim 13
Dependent Claim 159 words
A light emitting diode comprising: a second semiconductor layer formed on a principal plane of a wurtzite compound semiconductor crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of a semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; a pair of electrodes for supplying current to said second semiconductor, said active layer, and said third semiconductor layer in a film thickness direction; and said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy; wherein a c axis of a wurtzite compound semiconductor crystal intersects substantially orthogonally with a light emission direction vertical to the substrate surface.
Claim 14
Dependent Claim 159 words
A light emitting diode comprising: a second semiconductor layer formed on a principal plane of a wurtzite compound semiconductor crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of a semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; a pair of electrodes for supplying current to said second semiconductor, said active layer, and said third semiconductor layer in a film thickness direction; and said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy; wherein a c axis of a wurtzite compound semiconductor crystal intersects substantially orthogonally with a light emission direction vertical to the substrate surface.
Claim 15
Dependent Claim 26 words
A light emitting diode according to claim 11, wherein said c axis of said wurtzite compound semiconductor crystal intersects substantially orthogonally with a crystal growth direction.
Claim 16
Dependent Claim 22 words
A light emitting diode according to claim 11, wherein said wurtzite compound semiconductor crystal is III-V compound semiconductor formed of III nitride.
Claim 17
Dependent Claim 95 words
A display device comprising: a first group of light emitting diodes each formed of a wurtzite compound semiconductor crystal in which a light emission direction intersects substantially orthogonally with a c axis, said first group of light emitting diodes emitting light with a first polarization direction; and a second group of light emitting diodes each formed of a wurtzite compound semiconductor crystal in which a light emission direction intersects substantially orthogonally with a c axis, said second group of light emitting diodes emitting light with a second polarization direction perpendicular to said first polarization direction.
Claim 18
Dependent Claim 95 words
A display device comprising: a first group of light emitting diodes each formed of a wurtzite compound semiconductor crystal in which a light emission direction intersects substantially orthogonally with a c axis, said first group of light emitting diodes emitting light with a first polarization direction; and a second group of light emitting diodes each formed of a wurtzite compound semiconductor crystal in which a light emission direction intersects substantially orthogonally with a c axis, said second group of light emitting diodes emitting light with a second polarization direction perpendicular to said first polarization direction.
Claim 19
Dependent Claim 163 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, and active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction; wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy, and light is emitted vertically relative to said principal plane.
Claim 20
Dependent Claim 163 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, and active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction; wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy, and light is emitted vertically relative to said principal plane.
Claim 21
Dependent Claim 18 words
A semiconductor light emitting device according to claim 15, wherein said semiconductor of active layer is wurtzite nitride.
Claim 22
Dependent Claim 50 words
A semiconductor light emitting device according to claim 15, wherein said substrate is made of GaN, AlN or SiC, and said principal plane is a {1100} plane, a {1120} plane or a plane of said substrate inclined at -5 to +5 degree with said {1100} plane or said {1120} plane.
Claim 23
Dependent Claim 43 words
A semiconductor light emitting device according to claim 15, wherein said crystal substrate is formed of a LiAlO 2 substrate, said principal plane is either a {100} plane or face inclined at an angle of -5 to +5 degree with said {100} face.
Claim 24
Dependent Claim 27 words
A semiconductor light emitting device according to claim 15, wherein said active layer is formed of Al x Ga l-x-y In y N (where 0≦x≦1 and 0≦y≦1).
Claim 25
Dependent Claim 56 words
A semiconductor light emitting device according to claim 15, furthermore comprising a mirror layer formed beneath said second semiconductor layer or on said third semiconductor layer, and a resonator formed using said mirror layer as one end surface in a film thickness direction of said active layer, said second semiconductor layer, and said third semiconductor layer.
Claim 26
Dependent Claim 26 words
A semiconductor light emitting device according to claim 20, wherein a resonance wavelength of said resonator is a wavelength which renders photo luminescence light intensity maximum.
Claim 27
Dependent Claim 60 words
A semiconductor light emitting device according to claim 20, wherein said active layer is formed of any of a multiple quantum well layer having a multi-layered structure of a first layer made of GaN or InGaN and a second layer made of AlGaInN or GaN or InGaN, a GaN single layer, an InGaN single layer, and an AlGaInN single layer.
Claim 28
Dependent Claim 37 words
A semiconductor light emitting device according to claim 20, wherein said principal plane of said crystal substrate is a {1120} plane or a {1100} plane of an SiC substrate, or a {1102} plane of a sapphire substrate.
Claim 29
Dependent Claim 158 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and, a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction, wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy.
Claim 30
Dependent Claim 158 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate via a first semiconductor layer; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and, a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction, wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy.
Claim 31
Dependent Claim 18 words
A semiconductor light emitting device according to claim 24, wherein said semiconductor of active layer is wurtzite nitride.
Claim 32
Dependent Claim 51 words
A semiconductor light emitting device according to claim 24, wherein said crystal substrate is made of GaN, AlN or SiC, and said principal plane is a {1100} plane, a {1120} plane or a plane of said substrate inclined at -5 to +5 degree with said {1100} plane or said {1120} plane.
Claim 33
Dependent Claim 43 words
A semiconductor light emitting device according to claim 24, wherein said crystal substrate is formed of a LiAlO 2 substrate, said principal plane is either a {100} plane or face inclined at an angle of -5 to +5 degree with said {100} face.
Claim 34
Dependent Claim 25 words
A semiconductor light emitting device according to claim 24, wherein said active layer is formed of Al x Ga l-x-y In y N (where 0≦y≦1).
Claim 35
Dependent Claim 40 words
A semiconductor light emitting device according to claim 24, wherein said crystal substrate, said second semiconductor layer, said third semiconductor layer, and said active layer are cleaved along one of a {0001} plane, a {1100} plane and a {1120} plane.
Claim 36
Dependent Claim 42 words
A semiconductor light emitting device according to claim 24, wherein said principal plane of said crystal substrate is a facet with face orientation intersecting with {0001} plane, and said active layer formed on said facet is used as a light emitting portion.
Claim 37
Dependent Claim 54 words
A semiconductor light emitting device according to claim 30, wherein said facet is formed to have a face orientation perpendicular to either a {1100} plane or {1120} plane or a {0001} plane, and said {1100} plane or said {1120} plane or said {0001} plane is a cleavage plane on both ends of a resonator.
Claim 38
Dependent Claim 19 words
A semiconductor light emitting device according to claim 24, wherein the thickness of said active layer is 1-20 nm.
Claim 39
Dependent Claim 153 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction; wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy.
Claim 40
Dependent Claim 153 words
A semiconductor light emitting device comprising: a second semiconductor layer formed directly on a principal plane of a crystal substrate; an active layer formed on said second semiconductor layer and having an energy band gap which is smaller than an energy band gap of said second semiconductor layer, said active layer is made of semiconductor having uniaxial anisotropy; a third semiconductor layer formed on said active layer and having an energy band gap which is larger than an energy band gap of said active layer; and a pair of electrodes for supplying current to said second semiconductor layer, said active layer, and said third semiconductor layer in a film thickness direction; wherein said film thickness direction of at least said active layer is different from an axis of said uniaxial anisotropy, said active layer has triaxis anisotropy by applying distortion in a plane which is not perpendicular to a c axis exhibiting anisotropy.
Claim 41
Dependent Claim 18 words
A semiconductor light emitting device according to claim 33, wherein said semiconductor of active layer is wurtzite nitride.
Claim 42
Dependent Claim 50 words
A semiconductor light emitting device according to claim 33, wherein said substrate is made of GaN, AlN or SiC, and said principal plane is a {1100} plane, a {1120} plane or a plane of said substrate inclined at -5 to +5 degree with said {1100} plane or said {1120} plane.
Claim 43
Dependent Claim 43 words
A semiconductor light emitting device according to claim 33, wherein said crystal substrate is formed of a LiAlO 2 substrate, said principal plane is either a {100} plane or face inclined at an angle of -5 to +5 degree with said {100} face.
Claim 44
Dependent Claim 27 words
A semiconductor light emitting device according to claim 33, wherein said active layer is formed of Al x Ga l-x-y In y N (where 0≦x≦1 and 0≦y≦1).
Claim 45
Dependent Claim 40 words
A semiconductor light emitting device according to claim 33, wherein said crystal substrate, said second semiconductor layer, said third semiconductor layer, and said active layer are cleaved along one of a {0001} plane, a {1100} plane and a {1120} plane.
Claim 46
Dependent Claim 43 words
A semiconductor light emitting device according to claim 33, wherein said principal plane of said crystal substrate is a facet with face orientation intersecting with a {0001} plane, and said active layer formed on said facet is used as a light emitting portion.
Claim 47
Dependent Claim 52 words
A semiconductor light emitting device according to claim 39, wherein said facet is formed to have face orientation perpendicular to either a {1100} plane or a {1120} plane or a {0001} plane, and said {1100} or said {1120} plane or said {0001} is a cleavage plane on both ends of a resonator.
Claim 48
Dependent Claim 19 words
A semiconductor light emitting device according to claim 33, wherein the thickness of said active layer is 1-20 nm.

References Cited (Backward Citations)

US5604763A Cited
JPH08125275A Cited
US5625202A Cited

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