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US5373166A
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Modulated strain heterostructure light emitting device
Assignee: GlobalFoundries Inc
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Filing: 1993-09-24
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Granted: 1994-12-13
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Expires: 2013-09-24
Abstract
Abstract A heterostructure laser diode is provided with an active region that includes a ternary or quaternary semiconductor compound. The composition of the semiconductor compound forming the active region is modulated resulting in an active region with a modulated strain profile ( INCREMENT a/a), e.g., a triangular sawtooth-like strain profile, perpendicular to the laser diodes epitaxial layers, i.e., parallel to the z-axis. This permits the present invention to increase strain and avoid formation of misfit dislocations by compensation, i.e., by inserting strained layers having opposing strains.
Inventors
- 👤 Nicholas I. Buchan
- 👤 Willi Heuberger
- 👤 Peter Roentgen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:40
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S5/32; B; B82; B82Y; B82Y20/00; H01S5/3201; H01S5/323; H01S5/3235; H01S5/32391; H01S5/34; H01S5/3403; H01S5/3406
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
105 words
A heterostructure semiconductor laser diode comprising: a quaternary semiconductor compound active region comprised of sublayers stacked on top of each other, said sublayers being strained alternatively in a compressive and tensile mode; upper and lower cladding layers with at least one of said cladding layers providing a potential barrier, said active region being embedded between said cladding layers; wherein said sublayers provide said active region with a modulated strain profile which is perpendicular to said region; and wherein said active region further comprises at least one compressively strained sublayer and one tensile strained sublayer, said active region having a net strain approximately equal to zero.
Claim 2
Dependent Claim
105 words
A heterostructure semiconductor laser diode comprising: a quaternary semiconductor compound active region comprised of sublayers stacked on top of each other, said sublayers being strained alternatively in a compressive and tensile mode; upper and lower cladding layers with at least one of said cladding layers providing a potential barrier, said active region being embedded between said cladding layers; wherein said sublayers provide said active region with a modulated strain profile which is perpendicular to said region; and wherein said active region further comprises at least one compressively strained sublayer and one tensile strained sublayer, said active region having a net strain approximately equal to zero.
Claim 3
Dependent Claim
33 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said modulated strain of said active region is attained by varying the composition of said quaternary semiconductor compound of said active region.
Claim 4
Dependent Claim
49 words
The heterostructure semiconductor laser diode as recited in claim 2, wherein variations in composition in each of said sublayers stresses said sublayers to be alternatively in a compressive mode and in a tensile mode, thereby providing said active region with a sawtooth-like strain profile perpendicular to said active region.
Claim 5
Dependent Claim
49 words
The heterostructure semiconductor laser diode as recited in claim 2, wherein variations in composition in each of said sublayers stresses said sublayers to be alternatively in a compressive mode and in a tensile mode, thereby providing said active region with a sinusoidal strain profile perpendicular to said active region.
Claim 6
Dependent Claim
49 words
The heterostructure semiconductor laser diode as recited in claim 2, wherein variations in composition in each of said sublayers stresses said sublayers to be alternatively in a compressive mode and in a tensile mode, thereby providing said active region with a cosinusoidal strain profile perpendicular to said active region.
Claim 7
Dependent Claim
49 words
The heterostructure semiconductor laser diode as recited in claim 2, wherein variations in composition in each of said sublayers stresses said sublayers to be alternatively in a compressive mode and in a tensile mode, thereby providing said active region with a aperiodic strain profile perpendicular to said active region.
Claim 8
Dependent Claim
47 words
The heterostructure semiconductor laser diode as recited in claim 2, wherein variations in composition in each of said sublayers stresses said sublayers to be alternatively in a and in a tensile mode, thereby providing said active region with a non-analytical strain profile perpendicular to said active region.
Claim 9
Dependent Claim
44 words
The heterostructure semiconductor laser diode as recited in claim 1, further comprising an n-doped InP cladding layer and a p-doped cladding layer embedding said active region, said active region further comprising undoped or slightly doped In 1-y Ga y As y P 1-y sublayers.
Claim 10
Dependent Claim
49 words
The heterostructure semiconductor laser diode as recited in claim 8, wherein said sublayers further comprise a sublayer of In 0 .55 Ga 0 .45 As 0 .75 P 0 .25 under tensile strain and In 0 .95 Ga 0 .05 As 0 .4 P 0 .6 under compressive strain.
Claim 11
Dependent Claim
66 words
The heterostructure semiconductor laser diode as recited in claim 8, wherein the composition of said In 1-y Ga y As y P 1-y sublayers in said active region is In 0 .5 Ga 0 .5 As 0 .8 P 0 .2 is said sublayers under tensile strain and In 0 .95 Ga 0 .05 As 0 .4 P 0 .6 in said sublayers under compressive strain.
Claim 12
Dependent Claim
18 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said diode is a light emitting diode.
Claim 13
Dependent Claim
40 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said active region has a width ranging from 150 to 160 nanometers, and said upper and lower cladding layers have each a width ranging from 1500 to 2000 nanometers.
Claim 14
Dependent Claim
37 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said active region has a bandgap ranging from 0.95 to 1 eV., and each of said cladding layers has a bandgap approximately equal to 1.35 eV.
Claim 15
Dependent Claim
31 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said at least one tensile strained sublayer has a modulated strain profile with a .increment.a/a ranging from -0.73% to -0.9%.
Claim 16
Dependent Claim
29 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said at least one compressively strained sublayer has a modulated strain profile with a .increment.a/a equal to 0.9%.
Claim 17
Dependent Claim
67 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said at least one tensile strained sublayer has a modulated strain profile with a .increment.a/a ranging from -0.73% to -0.9% and said at least one compressively strained sublayer has a modulated strain profile with a .increment.a/a equal to 0.9%, and providing said active region with a net layer strain with a .increment.a/a approximately equal to zero.
Claim 18
Dependent Claim
26 words
The heterostructure semiconductor laser diode as recited in claim 1, wherein said alternating compressively strained and tensile strained sublayers are generated while growing said active region.
References Cited (Backward Citations)
JPH04346485A
Cited
US5251225A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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