EP0319954A2
Expired / Lapsed
EP
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Semiconductor laser device and method of manufacturing the same
Assignee: Toshiba Corp
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Filing: 1988-12-07
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Granted: —
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Expires: 2008-12-07
Abstract
Abstract A semiconductor laser device comprising a semiconductor substrate (10), a multi-layered mesa stripe (16) having an active layer (13) sandwiched between a semiconductor layer (11, 12) of the same conductivity type as that of the active layer (13) and a semiconductor layer (14) of the opposite conductivity type to that of the active layer (13), and formed on the substrate (10), a burying layers (20) having a refractive index smaller than that of active layer (13) and burying both sides of the mesa stripe (16), and a pair of electrodes (21, 22) for supplying a current to active layer (13). The mesa stripe (16) is constructed such that both sides of active layer (13) neighboring to the semiconductor layer of the opposite conductivity type (14) substantially coincide with those of semiconductor layer of the opposite conductivity type (14), and that active layer (13) has a width decreasing toward the boundary between active layer (13) and semiconductor layer (11, 12), thereby to form a waist portion (28) at the boundary, and in that a protective layer (30) is formed to fill the waist portion (28), thus covering at least both sides of the active layer (13). A method for manufacturing the semiconductor laser device having above mentioned features, wherein etching of the multi-layer structure of semiconductor is so controlled to form a V-shaped waist portion (28) at the boundary between active layer (13) and semiconductor layer of the same conductivity type (11, 12), and a protective layer (30) is selectively formed to fill the waist portion (28).
Inventors
- 👤 Akira C/O Patent Division Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 21:36
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/20; H01S5/22; H01S5/227; H01S5/2275
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
278 words
A semiconductor laser device comprising: a semiconductor substrate (10, 35, 50); a multi-layered mesa stripe (16, 40, 56) having a first semiconductor layer (11, 12, 36, 51) of a first conductivity type formed on said substrate (10, 35, 50), an active layer (13, 37, 53) of the first conductivity type formed on the first semiconductor layer (11, 12, 36, 51), and a second semiconductor layer (14, 38, 54) of a second conductivity type formed on the active layer (13, 37, 53), a burying layer (20, 44, 57) having a refractive index smaller than that of said active layer (13, 37, 53) and burying both sides of the mesa stripe; and a pair of electrodes (21, 22, 45, 46) for supplying a current to the active layer (13, 37, 53), characterized in that the cross section of said mesa stripe (16, 40, 56), perpendicular to the axis of said mesa stripe, is constructed such that both sides of said active layer (13, 37, 53) neighboring to the second semiconductor layer (14, 38, 54) substantially coinside with those of said second semiconductor layer (14, 38, 54), and that said active layer (13, 37, 53) has a width decreasing toward the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51), thereby to form a waist portion (28, 48) at the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51); and in that a protective layer (30, 49, 60) is formed to fill the waist portion (28, 48, 59) of said mesa stripe, thus covering at least both sides of the active layer (13, 37, 53).
Claim 2
Dependent Claim
278 words
A semiconductor laser device comprising: a semiconductor substrate (10, 35, 50); a multi-layered mesa stripe (16, 40, 56) having a first semiconductor layer (11, 12, 36, 51) of a first conductivity type formed on said substrate (10, 35, 50), an active layer (13, 37, 53) of the first conductivity type formed on the first semiconductor layer (11, 12, 36, 51), and a second semiconductor layer (14, 38, 54) of a second conductivity type formed on the active layer (13, 37, 53), a burying layer (20, 44, 57) having a refractive index smaller than that of said active layer (13, 37, 53) and burying both sides of the mesa stripe; and a pair of electrodes (21, 22, 45, 46) for supplying a current to the active layer (13, 37, 53), characterized in that the cross section of said mesa stripe (16, 40, 56), perpendicular to the axis of said mesa stripe, is constructed such that both sides of said active layer (13, 37, 53) neighboring to the second semiconductor layer (14, 38, 54) substantially coinside with those of said second semiconductor layer (14, 38, 54), and that said active layer (13, 37, 53) has a width decreasing toward the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51), thereby to form a waist portion (28, 48) at the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51); and in that a protective layer (30, 49, 60) is formed to fill the waist portion (28, 48, 59) of said mesa stripe, thus covering at least both sides of the active layer (13, 37, 53).
Claim 3
Dependent Claim
74 words
The semiconductor laser device according to claim 1, characterized in that said first semiconductor layer is comprised of a buffer layer (11) formed on said substrate and an optical wave-guiding layer (12) formed on the buffer layer (11), said waist portion (28, 48) is formed at the boundary between said active layer (13, 37, 53) and said optical wave-guiding layer (12), and said second semiconductor layer (14, 38, 54) includes a cladding layer (14).
Claim 4
Dependent Claim
36 words
The semiconductor laser device according to claim 1, characterized in that said cladding layer (14) has a width gradually decreasing toward said active layer, and has a waist located near said active layer (13, 37, 53).
Claim 5
Dependent Claim
25 words
The semiconductor laser device according to claim 1, characterized in that said first semiconductor layer comprises a buffer layer (11) formed on said substrate (10).
Claim 6
Dependent Claim
26 words
The semiconductor laser device according to claim 1, characterized in that said first semiconductor layer comprises an optical wave-guiding layer (12) formed on said substrate (10).
Claim 7
Dependent Claim
22 words
the semiconductor laser device according to claim 1, characterized in that said protective layer (30, 49, 60) is made of semiconductor material.
Claim 8
Dependent Claim
22 words
The semiconductor laser device according to claim 1, characterized in that said protective layer (30, 49, 60) is made of insulative material.
Claim 9
Dependent Claim
25 words
The semiconductor laser device according to claim 1, characterized in that said protective layer (30, 49, 60) is formed by virtue of mass transport phenomenon.
Claim 10
Dependent Claim
22 words
The semiconductor laser device according to claim 1, characterized in that said burying layer (20, 44, 59) is made of semiconductor material.
Claim 11
Dependent Claim
22 words
The semiconductor laser device according to claim 1, characterized in that said burying layer (20, 44, 57) is made of high-resistance material.
Claim 12
Independent Claim
282 words
A method of manufacturing a semiconductor laser device, comprising the steps of: (i) forming, on a semiconductor substrate (10, 35, 50), a first semiconductor layer (11, 12, 36, 51) of a first conductivity type, an active layer (13, 37, 53) of the first conductivity type on the first semiconductor layer (11, 12, 36, 51), and a second semiconductor layer (14, 38, 54) of a second conductivity type on the active layer (13, 37, 53), thereby forming a multi-layer structure of semiconductor; (ii) etching the multi-layer structure of semiconductor, thus forming a mesa stripe (16, 40, 56); (iii) forming burying layer (20, 44, 57) having a refractive index smaller than that of the active layer, to bury sides of the mesa stripe (16, 40, 56) and (iv) forming a pair of electrodes (21, 22, 45, 46) for supplying a current to said active layer; characterized in that said step (ii) comprises the steps of: (iia) forming said mesa stripe (16, 40, 56) having a cross section perpendicular to the axis of the mesa stripe, (16, 40, 56), characterized in that both sides of the active layer neighboring to the second semiconductor layer substantially coinside with those of said second semiconductor layer (14, 38, 54), and said active layer (13, 37, 53) has a width decreasing toward the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51) so as to form a waist portion (28, 48, 59) at said boundary; and (iib) forming a protective layer (30, 49, 60) burying the waist portion (28, 48) of the mesa stripe (16, 40, 56), thus covering at least both exposed sides of said active layer (13, 37, 53).
Claim 13
Independent Claim
282 words
A method of manufacturing a semiconductor laser device, comprising the steps of: (i) forming, on a semiconductor substrate (10, 35, 50), a first semiconductor layer (11, 12, 36, 51) of a first conductivity type, an active layer (13, 37, 53) of the first conductivity type on the first semiconductor layer (11, 12, 36, 51), and a second semiconductor layer (14, 38, 54) of a second conductivity type on the active layer (13, 37, 53), thereby forming a multi-layer structure of semiconductor; (ii) etching the multi-layer structure of semiconductor, thus forming a mesa stripe (16, 40, 56); (iii) forming burying layer (20, 44, 57) having a refractive index smaller than that of the active layer, to bury sides of the mesa stripe (16, 40, 56) and (iv) forming a pair of electrodes (21, 22, 45, 46) for supplying a current to said active layer; characterized in that said step (ii) comprises the steps of: (iia) forming said mesa stripe (16, 40, 56) having a cross section perpendicular to the axis of the mesa stripe, (16, 40, 56), characterized in that both sides of the active layer neighboring to the second semiconductor layer substantially coinside with those of said second semiconductor layer (14, 38, 54), and said active layer (13, 37, 53) has a width decreasing toward the boundary between said active layer (13, 37, 53) and said first semiconductor layer (11, 12, 36, 51) so as to form a waist portion (28, 48, 59) at said boundary; and (iib) forming a protective layer (30, 49, 60) burying the waist portion (28, 48) of the mesa stripe (16, 40, 56), thus covering at least both exposed sides of said active layer (13, 37, 53).
Claim 14
Dependent Claim
67 words
The method according to claim 11, characterized in that said process of forming said first semiconductor layer is to form a buffer layer (11) on said substrate (10) and also an optical wave-guiding layer (12) formed on the buffer layer (11), or to form one of these layers; and said process of forming said second semiconductor layer is to form a layer including a cladding layer (14).
Claim 15
Dependent Claim
49 words
The method according to claim 11, characterized in that said step (ii) includes a process of forming a waist portion (28, 48) in said cladding layer (14, 38, 54), whose width gradually decreases toward said active layer (13, 37), and which is located near said active layer (13, 37).
Claim 16
Dependent Claim
28 words
The method according to claim 11, characterized in that the protective layer (30, 49, 60) formed in said step (iii) is made of semiconductor material or insulative material.
Claim 17
Dependent Claim
28 words
The method according to claim 11, characterized in that said step (iii) of forming the protective layer (30, 49, 60) is performed by virtue of mass transport phenomenon.
Claim 18
Dependent Claim
28 words
The method according to claim 11, characterized in that the burying layer (20, 44, 57) formed in said step (iv) is made of semiconductor material or high-resistance material.
References Cited (Backward Citations)
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