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US 6,185,238 B2Granted
Nitride compound semiconductor laser and its manufacturing method
AssigneeKabushiki Kaisha Toshiba
InventorsMasaaki Onomura, Genichi Hatakoshi, Shinya Nunoue, Masayuki Ishikawa
Life of this patent
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Abstract
In a nitride compound semiconductor laser including an active layer sandwiched by semiconductor layers of different conduction types on a sapphire substrate, layers of polyimide for current blocking and light confinement are formed on side surfaces of a mesa-type current confining structure with and under the p-side electrode. The laser ensures efficient, uniform carrier injection into the active layer, suppresses higher-order modes other than the fundamental transverse mode, and thereby promises a high reliability ensuring continuous pulsation under a low threshold current and a low operation voltage with low noise characteristics.
Claims23
A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer and a second cladding layer of a second conduction type overlying said active layer;
- and
- current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with an insulator,
- said current blocking layers extending in a direction perpendicular to a light emitting facet and said current blocking layers being not exposed to side surfaces of said multi-layered structure perpendicular to said light emitting facet, wherein said multi-layered structure further comprises a contact layer of a first conduction type and an electrode in contact with said contact layer, the relation of W1≦4·W2 being established where W1 is the distance between every adjacent two current blocking layers and W2 is the thickness of said contact layer.
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A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer, and a second cladding layer of a second conduction type overlying said active layer;
- and
- current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with an insulator;
- wherein said multi-layered structure further comprises a contact layer of a first conduction type and an electrode in contact with said contact layer, the relation of W1≦4·W2 being established where W1 is the distance between every adjacent two current blocking layers and W2 is the thickness of said contact layer.
1 more element
A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer, and a second cladding layer of a second conduction type overlying said active layer;
- and
- at least three current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with an insulator,
- wherein said at least three current blocking layers are unequally distant.
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A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer, and a second cladding layer of a second conduction type overlying said active layer;
- and
- current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with a gallium nitride compound semiconductor of said first conduction type and having a composition different from the compositions of said active layer and said second cladding layer.
- said current blocking layers extending in a direction perpendicular to a light emitting facet and said current blocking layers being not exposed to side surfaces of said multi-layered structure perpendicular to said light emitting facet, wherein said multi-layered structure further comprises a contact layer of a first conduction type and an electrode in contact with said contact layer, the relation of W1≦4·W2 being established where W1 is the distance between every adjacent two current blocking layers and W2 is the thickness of said contact layer.
1 more element
A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer, and a second cladding layer of a second conduction type overlying said active layer;
- and
- current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with a gallium nitride compound semiconductor of said first conduction type,
- wherein said multi-layered structure further comprises a contact layer of a first conduction type and an electrode in contact with said contact layer, the relation of W1≦4·W2 being established where W1 is the distance between every adjacent two current blocking layers and W2 is the thickness of said contact layer.
1 more element
A nitride compound semiconductor laser comprising:
- a multi-layered structure made of gallium nitride compound semiconductors GaxInyAlzN where x+y+z=1, 0≦x≦1, 0≦y≦1 and 0≦z≦1, including, at least, a first cladding layer of a first conduction type, an active layer overlying said first cladding layer, and a second cladding layer of a second conduction type overlying said active layer;
- and
- at least three current blocking layers made by forming at least two grooves extending on the major surface of said multi-layered structure closer to said second cladding layer and by filling said grooves with a gallium nitride compound semiconductor of said first conduction type,
- wherein said at least three current blocking layers are unequally distant.
1 more element
Dependencies are inferred from the claim text.