Patent EP0038085A1 successfully refreshed from Google Patents.
EP0038085A1
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EP
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Buried heterostructure laser diode and method for making the same
Assignee: NEC Corp
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Filing: 1981-04-15
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Granted: —
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Expires: 2001-04-15
Abstract
Abstract The buried heterostructure laser diode [BHLD] is made of InGaAsP crystal layers on an InP substrate. <??>To provide a BHLD having an improved linearity of the active layer stripe and a reduced optical waveguide loss and to provide a plurality of BHLDs having different lasing wavelenghts formed on the same substrate the BHLD of the invention has such structure that an active layer is provided in a semiconductor region forming a mesa stripe, and except for the top surface portion of the mesa stripe the side surface portion of the mesa stripe and the reminder are covered by a current blocking layer. A current confining layer covers only this current blocking layer and a clad layer covers this current blocking layer and the top surface portion of the mesa stripe. <??>A method for producing the above BHLD includes the processes of uniformly growing a necessary layer or layers and an active layer on a substrate then forming a mesa stripe including the active layer so as to have a predetermined stripe width, thereafter selectively growing a current blocking layer and a current confining layer successively on the mesa-shaped structure except for the top surface of the mesa stripe, and subsequently growing a clad layer on the top surface of the mesa stripe and on the current confining layer.
Inventors
- 👤 Ikuo Mito
- 👤 Mitsuhiro Kitamura
- 👤 Kazuhisa Kaede
- 👤 Kohroh Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 20:26
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/227; H01S5/40; H01S5/4025; H01S5/4031; H01S5/4043; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H01S5/2275; H01S5/30; H01S5/32; H01S5/323; H01S5/3235; H01S5/32391
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
227 words
A buried heterostructure laser diode comprising a semiconductor crystal having a pair of principal surfaces and a pair of reflective end surfaces constituting an optical resonator, and a pair of electrodes, said semiconductor crystal including a base semiconductor region having a mesa portion and having a first conductivity type, said mesa portion being elongating between said pair of reflective end surfaces in a stripe geometry, said semiconductor crystal further including a first semiconductor layer only provided on a top surface of said mesa portion, having a band gap smaller than that of said base region and extending between said pair of reflective end surfaces in a stripe geometry, a pair of second semiconductor layers provided on said base region, covering side surfaces of said first layer and side surfaces of said mesa portion and having a second conductivity type and a band gap larger than that of said first layer, a pair of third semiconductor layers only provided on the top surfaces of said second layers and having said first conductivity type and a band gap larger than that of said first layer, and a fourth semiconductor layer commonly provided on the top surfaces of said first layer and said third layers and having said second conductivity type and a band gap larger than that of said first layer, said electrodes being provided on said principal surfaces.
Claim 2
Dependent Claim
227 words
A buried heterostructure laser diode comprising a semiconductor crystal having a pair of principal surfaces and a pair of reflective end surfaces constituting an optical resonator, and a pair of electrodes, said semiconductor crystal including a base semiconductor region having a mesa portion and having a first conductivity type, said mesa portion being elongating between said pair of reflective end surfaces in a stripe geometry, said semiconductor crystal further including a first semiconductor layer only provided on a top surface of said mesa portion, having a band gap smaller than that of said base region and extending between said pair of reflective end surfaces in a stripe geometry, a pair of second semiconductor layers provided on said base region, covering side surfaces of said first layer and side surfaces of said mesa portion and having a second conductivity type and a band gap larger than that of said first layer, a pair of third semiconductor layers only provided on the top surfaces of said second layers and having said first conductivity type and a band gap larger than that of said first layer, and a fourth semiconductor layer commonly provided on the top surfaces of said first layer and said third layers and having said second conductivity type and a band gap larger than that of said first layer, said electrodes being provided on said principal surfaces.
Claim 3
Dependent Claim
25 words
A buried heterostructure laser diode as claimed in Claim 1, in which said first layer includes a plurality of semiconductor layers having different band gaps.
Claim 4
Dependent Claim
49 words
A buried heterostructure laser diode as claimed in Claim 1, in which said first layer has a width in a range of 2 - - 2. 5 µm and a hight of a mesa portion combined with said first layer has a range .of 1. 3 - 2 µm.
Claim 5
Independent Claim
171 words
A method for producing a buried heterostructure laser diode comprising the steps of providing a first semiconductor layer on a base semiconductor crystal having a first conducitivity type, said first layer having a band gap smaller than that of said base crystal, forming a mesa-stripe portion extending along a predetermined direction by selectively removing said first layer and part of said base crystal, providing a pair of second semiconductor layers only on the removed surfaces of said base crystal and said first layer, said second layer having a second conductivity type and a band gap larger than that of said first layer, providing a pair of third layers only on a pair of top surfaces of said second layers, said third layers having said first conductivity and a band gap larger than that of said first layer, and providing a fourth layer on the top surfaces of said first and third layers, said fourth layer having said second conductivity type and a band gap larger than that of said first layer.
Claim 6
Independent Claim
171 words
A method for producing a buried heterostructure laser diode comprising the steps of providing a first semiconductor layer on a base semiconductor crystal having a first conducitivity type, said first layer having a band gap smaller than that of said base crystal, forming a mesa-stripe portion extending along a predetermined direction by selectively removing said first layer and part of said base crystal, providing a pair of second semiconductor layers only on the removed surfaces of said base crystal and said first layer, said second layer having a second conductivity type and a band gap larger than that of said first layer, providing a pair of third layers only on a pair of top surfaces of said second layers, said third layers having said first conductivity and a band gap larger than that of said first layer, and providing a fourth layer on the top surfaces of said first and third layers, said fourth layer having said second conductivity type and a band gap larger than that of said first layer.
Claim 7
Independent Claim
137 words
A method for making a buried heterostructure laser diode comprising a first epitaxial growth process for preparing a multi-layer structure wafer including at least an In 1-x Ga x As 1-y Py (0 < x < 1 and 0 < y < 1) active layer stacked on an n-type InP substrate having a (001) oriented or nearly (001) oriented surface, a process for forming a mesa stripe having a multi-layer structure by etching said multi-layer structure wafer along the< 110>directions deeper than said In 1-x Ga x As 1-y Py active layer, and a second epitaxial growth process for successively growing a p-type InP current blocking layer and an n-type InP current confining layer on said wafer except for the top surface of said mesa stripe, and a p-type InP embedding layer on the entire wafer surface.
Claim 8
Independent Claim
137 words
A method for making a buried heterostructure laser diode comprising a first epitaxial growth process for preparing a multi-layer structure wafer including at least an In 1-x Ga x As 1-y Py (0 < x < 1 and 0 < y < 1) active layer stacked on an n-type InP substrate having a (001) oriented or nearly (001) oriented surface, a process for forming a mesa stripe having a multi-layer structure by etching said multi-layer structure wafer along the< 110>directions deeper than said In 1-x Ga x As 1-y Py active layer, and a second epitaxial growth process for successively growing a p-type InP current blocking layer and an n-type InP current confining layer on said wafer except for the top surface of said mesa stripe, and a p-type InP embedding layer on the entire wafer surface.
References Cited (Backward Citations)
US4230997A
Cited
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