GB2129211A - Semiconductor laser and a method of making same - Google Patents
Semiconductor laser and a method of making same Download PDFInfo
- Publication number
- GB2129211A GB2129211A GB08230129A GB8230129A GB2129211A GB 2129211 A GB2129211 A GB 2129211A GB 08230129 A GB08230129 A GB 08230129A GB 8230129 A GB8230129 A GB 8230129A GB 2129211 A GB2129211 A GB 2129211A
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- substrate
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- ridge
- semiconductor laser
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- 239000004065 semiconductor Substances 0.000 title claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000000758 substrate Substances 0.000 claims abstract description 64
- 239000000463 material Substances 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000000151 deposition Methods 0.000 claims abstract description 11
- 238000005530 etching Methods 0.000 claims abstract description 9
- 239000011248 coating agent Substances 0.000 claims abstract 3
- 238000000576 coating method Methods 0.000 claims abstract 3
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 claims 1
- 229910052738 indium Inorganic materials 0.000 claims 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims 1
- GPXJNWSHGFTCBW-UHFFFAOYSA-N Indium phosphide Chemical compound [In]#P GPXJNWSHGFTCBW-UHFFFAOYSA-N 0.000 description 9
- 150000001875 compounds Chemical class 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 238000004943 liquid phase epitaxy Methods 0.000 description 3
- 238000000927 vapour-phase epitaxy Methods 0.000 description 3
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000000873 masking effect Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000010186 staining Methods 0.000 description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910000756 V alloy Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000001947 vapour-phase growth Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
- H10H20/01—Manufacture or treatment
- H10H20/011—Manufacture or treatment of bodies, e.g. forming semiconductor layers
- H10H20/013—Manufacture or treatment of bodies, e.g. forming semiconductor layers having light-emitting regions comprising only Group III-V materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
- H01S5/22—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers having a ridge or stripe structure
- H01S5/223—Buried stripe structure
- H01S5/2232—Buried stripe structure with inner confining structure between the active layer and the lower electrode
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
- H01S5/22—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers having a ridge or stripe structure
- H01S5/223—Buried stripe structure
- H01S5/2232—Buried stripe structure with inner confining structure between the active layer and the lower electrode
- H01S5/2234—Buried stripe structure with inner confining structure between the active layer and the lower electrode having a structured substrate surface
- H01S5/2235—Buried stripe structure with inner confining structure between the active layer and the lower electrode having a structured substrate surface with a protrusion
Landscapes
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
Abstract
A semiconductor laser includes a semiconductor body having parallel end faces 34 and a substrate on a major surface of which, and/or of a buffer layer 44 overlying the substrate, there is a ridge 46 which extends between the end surfaces. An active layer 50 overlies the ridge and tapers in thickness from that portion of the active layer which overlies the ridge. A confinement layer 52 overlies the active layer. A method of forming such a semiconductor laser includes the steps of coating a portion of a flat surface of the substrate, on which there may be a buffer layer, with an etch resistant material, etching with an anisotropic etchant thereby forming a mesa, removing the etch resistant material, further etching to round the mesa to form a ridge, and depositing the active and confinement layers over the surface and the ridge. <IMAGE>
Description
SPECIFICATION
Semiconductor laser and a method of making same
This invention relates to a semiconductor laser having a substrate with a rounded ridge in a surface thereof extending between the end faces of the laser and a method of making this laser.
A semiconductor laser includes a body of semiconductor material, generally composed of group Ill-V compounds, having a thin active layer between layers of opposite conductivity type, i.e., a layer of P-type conductivity on one side of the active layer and a layer of N-type conductivity on the other side of the active layer. Such a laser, however, typically emits light in more than one optical mode which limits its utility. Botez, in U.S.
Patent 4,215,319 issued July 29, 1980 and entitled Single Filament Semiconductor laser, has disclosed a laser having a stable, single mode, output light beam. The control over the output light beam from this laser arises from the tapering in thickness of the layers. This laser is prepared by deposition of the confinement and active layers onto a substrate having a pair of substantially parallel grooves therein. The tapering is caused by the difference in growth rate of the layers over a land between the grooves and over the grooves when the layers are prepared by liquid or vapor phase epitaxy techniques.
However, if the layers are deposited on an indium phosphide substrate having such a pair of parallel grooves, using either liquid phase or vapor phase epitaxy, flat, planar surfaces are observed with the grooves filling faster than the flat substrate portions until a continuous, smooth surface is obtained. This growth habit of InP limits the utilization of the structure disclosed by Botez for lasers composed of InP and related alloys. It would be desirable to have a laser composed of InP and related alloys which exhibits the tapered layer structure characteristic of the laser disclosed by
Botez.
We have discovered that when a laser is formed on a substrate having a ridge therein, the deposited layers have curved surfaces with the desired taper in thickness. The semiconductor laser of the invention includes a body of semiconductor material having a pair of end surfaces and a substrate having one or more ridges therein extending between the end faces. An active layer overlying the surface of the substrate and the ridges tapers in thickness in the lateral direction (a direction in the plane of the surface of the substrate and perpendicular to the axis of the ridges). A confinement layer overlies the active layer.
The method of forming this laser includes the steps of depositing a layer of an etch resistant material on a portion of the substrate, etching the uncovered portions of the surface of the substrate, removing the etch resistant material and leaving a mesa in the substrate surface, further etching the surface thereby forming a ridge therein and depositing the active and confinement layers sequentially over the surface of the substrate and the ridge.
In the accompanying drawings:
Figure 1 is a schematic illustration of a perspective view of a semiconductor laser of the invention.
Figure 2 is a schematic illustration of a cross sectional view of a second embodiment of the semiconductor laser of the invention.
Figure 3 is a schematic illustration of the steps of the method of the invention.
Figure 4 is a photomicrograph of a cross section of the semiconductor laser of the invention.
Referring to Fig. 1, a semiconductor laser 30 includes a semiconductor body 32 having spaced parallel end faces 34, at least one of which is partially transmissive of light at the wavelength of the output laser beam, and a pair of side surfaces 36 extending between the end faces 34. The semiconductor body 32 includes a substrate 38 having a pair of opposed major surfaces 40 and 42. A buffer layer 44 overlies the major surface 40 and has a rounded ridge 46 in a surface 48 thereof which extends between the end faces 34 of the body 32. An active layer 50 overlies the ridge 46 and the surface 48 of the buffer layer 44 and tapers in thickness in the lateral direction. A confinement layer 52 overlies the active layer 50 and a capping layer 54 overlies the confinement layer 52.An electrically insulating layer 56 overlies the capping layer 54 and has an opening extending therethrough in the form of a stripe 58 which is over the ridge 46 in the buffer layer 44. A first electrically conducting layer 60 overlies the electrically insulating layer 56 and the surface of the capping layer 54 in the region of the stripe 58.
A second electrically conducting layer 62 overlies the second major surface 42 of the substrate 38.
The first and second electrically conducting layers 60 and 62 respectively form the electrical contacts to the body 32.
Referring to Fig. 2 the identification of the elements common to a semiconductor laser 70 and the semiconductor laser 30 of Fig. 1 is the same. The semiconductor laser 70 differs from the semiconductor laser 30 in that there are a pair of rounded ridges 46 in the substrate 38 with the buffer layer 44 overlying the substrate and ridges.
The active layer 50 then overlies the buffer layer 44 and tapers in thickness in the region over a land 72 between the ridges 46.
The substrate 38 is typically composed of a binary group Ill-V compound or an alloy of such compounds having a surface 40 which is parallel to the (100) or (110) crystallographic plane. The substrate may be slightly misoriented from one of these orientations but preferably either a (100) or (110) plane is used. However, it is to be understood that other substrate orientations may also be used. In the selection of the substrate and the layers deposited thereon, it is desirable that the layers be lattice matched to the substrate.
Preferably the substrate is composed of N-type
InP.
The buffer layer 44 is typically composed of the same material as the substrate and is used to provide a high quality surface upon which the overlying layers can be deposited. Typically this
layer is between about 3 and about 10 micrometers thick. If the ridges 46 are in the substrate 38 a buffer layer may be interposed between the substrate 38 and active layer 50.
The rounded ridges 46 are shown in Figs. 1 and 2 as being in the buffer layer 44 and the substrate 38 respectively. The ridges may be between about 5 and about 20 micrometers wide at their base and between about 0.2 and about
10 micrometers in height. The height and width are chosen so as to provide the desired curvature of the layers deposited thereon. If more than one ridge is present, the spacing between the ridges as well as the height and width of the individual ridges is chosen so as to provide the desired curvature of the layers deposited thereon.
Typically, the center-to-center spacing of the ridges is between about 10 and about 100 micrometers.
The ridges may be formed using the sequence of steps shown in Fig. 3. In Fig. 3(a) the substrate 102 is coated with a buffer layer 104. Portions of the surface 106 of the buffer layer 104 are then coated with a masking layer 108 of etch resistant material such as an oxide of silicon, using standard photolithographic and deposition techniques.The surface 106 is then etched with an anisotropic etchant such as 0.1 to 1.0 percent bromine in methanol which etches the exposed portion of the buffer layer 104 and forms mesas 110 in the surface 112 of the buffer layer 104 as shown in Fig. 3(b). The masking layer 108 is then removed leaving the mesas 110 and the surface 112 as shown in Fig. 3(c). The mesas 110 and surface 11 2 are then further etched using the same or a different etchant to round off the mesas thereby forming the rounded ridges 120 in the surface 122 of the buffer layer 104 as shown in Fig. 3(d). The active, confinement and capping layers are then sequentially deposited over the ridges 120 and surface 122.It is clear that the ridges could equally well have been formed in the substrate itself followed by the sequential deposition of the layers.
The various epitaxial layers may be deposited on the substrate 38 of Fig. 1 using techniques of liquid phase epitaxy such as are disclosed by H. F.
Lockwood et al in U.S. Patent 3,753,801 entitled
Method of Depositing Epitaxial Semiconductor
Layers from the Liquid Phase, issued August 21, 1973 and which is incorporated herein by reference. Alternatively, the layers may be deposited by vapor phase epitaxy using techniques such as are disclosed by Olsen et al in
U.S. Patent 4,116,733 entitled Vapor Phase
Growth Technique of Ill-V Compounds Utilizing a
Pre-heating Step, issued September 26, 1 978 and incorporated herein by reference. Using these techniques, layers with taper in thickness can be deposited since the local growth rate of an individual layer will vary with the local curvature of the surface upon which it is grown; the greater the amount of local positive curvature of the surface, the higher the local growth rate.
The active layer is typically between about 0.05 and about 2.2 micrometers thick and is preferably between about 0.1 and about 0.5 micrometer thick. This layer is either undoped or lightly P- or N-type conducting and may be composed of an InGaAsP or InGaAs alloy where the relative concentration of the elements is chosen to provide an approximate lattice match to the buffer layer and an output light beam of the desired wavelength, as disclosed, for example, by
Olsen et al in the Journal of Electronic Materials 9,977(1980).
The confinement layer 52 is typically composed of P-type InP and is between about 0.5 and about 3 micrometers thick. The capping layer 54 may be used to improve the quality of the electrical contact made to the laser 30. It is typically between about 0.2 and about 0.5 micrometer thick and is composed of InGaAsP or
InGaAs having the same conductivity type as the confinement layer 52.
It is to be understood that the devices of the invention can be fabricated using other combinations of group ill--V alloys.
The electrically insulating layer 56 is preferably composed of silicon dioxide which may be deposited on the capping layer 38 by pyrolytic decomposition of a silicon-containing gas, such as silane, in oxygen or water vapor. The strip 58 is formed through the electrically insulating layer 56 down to the capping layer 54 using standard photolithographic and etching techniques and is preferably located over the ridge 46 when a single ridge is present. Alternatively, if two ridges are used, then the stripe 58 is located over the land between the ridges.
The electrically conducting layer 60 is preferably composed of titanium, platinum and gold and is deposited by sequential evaporation.
One skilled in the art would realize that it is only necessary that the electrically conducting layer overlie the confinement layer in the region over the ridge 46 in a device having a single ridge.
Alternatively, the electrically insulating layer 56 may be eliminated by depositing on the confinement layer 52 a blocking layer of opposite conductivity type to the confinement layer 52 which has a region therein of the same conductivity type as the confinement layer. The electrically conducting layer 60 then may overlie the entire surface of this blocking layer. Upon application of a bias voltage to the laser 30 the p-n junction between the blocking layer and the confinement layer is reverse biased except in the region of this layer which has been converted to the same conductivity type as the confinement layer 52.
The electrically conducting layer 62 on the second major surface 42 of the substrate 38 may be formed by vacuum deposition and sintering of tin and gold.
An end face 34 of the laser 30 is typically
coated with a layer of aluminum oxide or similar
material having a thickness of about one half
wave at the lasing wavelength. Such a layer has
been disclosed by Ladany et al in U.S. Patent
4,178,564 issued December 11, 1979 and
entitled Half Wave Protection Layers on Injection
Lasers. The opposed end face 34 may be coated
with a mirror which is reflecting at the lasing
wavelength. Such as disclosed by Caplan et al in
U.S. Patent No. 3,701,047 issued October 24,
1972, entitled Semiconductor Laser Devices
Utilizing Light Reflective Metallic Layers and
Ettenberg in U.S. Patent 4,092,659 issued May 30, 1 978 and entitled Multi-Layer Reflector for
Electroluminescent Device.
Referring to Fig. 4 a photomicrograph of a
cross secton of a laser 1 50 constructed according to the principles of the invention and having the
desired taper includes an InP substrate 152
having an InP buffer layer thereon which has a
ridge 154 therein. An InGaAsP active layer 156 which is about 300 nanometers thick overlies the surface of the buffer layer. An InP confinement
layer 158 overlies the active layer and an
InGaAsP capping layer 160 overlies the
confinement layer. The layers are distinguished from one another by the use of staining techniques which are well known in the art. A demarkation between the substrate 152 and the
buffer layer cannot be seen because they are composed of the same material and thus the staining will affect both in the same way. The
ridge 154 in the buffer layer is asymmetric
because the substrate surface was slightly
misoriented from the (110) direction. For the
purpose of the claims which follow, a buffer layer,
when present, is considered as part of the - substrate.
Claims (13)
1. A semiconductor laser comprising
a semiconductor body having two end faces at
least one of which is partially transmissive of
light, a substrate having opposed major
surfaces and a ridge in a major surface
thereof which extends between the two end
faces;
an active layer overlying the substrate and
tapering in thickness in the lateral direction
from the portion thereof which overlies the
ridge;
a confinement layer overlying the active layer;
a first electrically conducting layer overlying a
portion of the confinement layer over the
ridge; and
a second electrically conducting layer overlying
a portion of the second major surface of the
substrate;
wherein the substrate is of one conductivity
type and the confinement layer and the
capping layer of the opposite conductivity
type and wherein the index of refraction of
the active layer is greater than that of the
substrate and that of the confinement layer.
2. A semiconductor laser according to claim 1 further comprising
a capping layer overlying the confinement layer
and an electrically insulating layer overlying
the capping layer and having an opening
extending therethrough, wherein the first
electrically conducting layer overlies the
capping layer in the opening in the
electrically insulating layer.
3. A semiconductor laser according to claim 1 or 2 wherein the substrate includes a buffer layer underlying the active layer and having the ridge therein.
4. A semiconductor laser according to claim 3 wherein the substrate, the buffer layer and the confinement layer are composed of InP and the active layer is composed of InGaAsP.
5. A semiconductor laser comprising a body composed of InP and alloys containing indium and phosphorous having two end faces at least one of which is partially transmissive to light and a substrate having opposed major surfaces and a ridge in a major surface thereof which extends between the two end faces;
an active layer, composed of InGaAsP,
overlying the substrate and tapering in
thickness from the portion thereof which
overlies the ridge;
a confinement layer, composed of InP,
overlying the active layer;
a capping layer, composed of InGaAsP,
overlying the confinement layer;
an electrically insulating layer overlying the
capping layer and having an opening
therethrough;
a first electrically conducting layer overlying
the electrically insulating layer and the
portion of the capping layer exposed in the
opening; and
a second electrically conducting layer overlying
a portion of the second major surface of the
substrate;
wherein the substrate is of one conductivity
type and the confinement layer and the
capping layer of the opposite conductivity
type and wherein the index of refraction of
the active layer is greater than that of the
substrate and that of the confinement layer.
6. A semiconductor laser according to claim 5 wherein the substrate is of InP and includes a
buffer layer underlying the active layer and having the ridge therein.
7. A semiconductor laser according to any preceding claim wherein spaced apart from and substantially parallel to the ridge in the substrate there is a second ridge in the substrate with the active layer tapering in thickness from that portion over a land between the ridges in the substrate.
8. A method of making a semiconductor laser comprising the steps of
coating a portion of a surface of a
semiconductor substrate with an etch
resistant material;
etching said surface with an anisotropic
etchant whereby a mesa is formed in said
surface;
removing the etch resistant material;
etching said surface and the mesa therein
whereby a ridge is formed in the surface of
the substrate;
depositing an active layer over the ridge and
said surface of the substrate whereby the
active layer tapers in thickness in the lateral
direction;
depositing a confinement layer over the active
layer; and depositing electrically conducting
layers over portions of the confinement layer
and an opposed surface of the substrate.
9. A method of making a substrate having a ridge therein comprising the steps of
coating a portion of a surface of the
semiconductor substrate with an etch
resistant material;
etching said surface with an anisotropic
etchant whereby a mesa is formed in said
surface;
removing the etch resistant material; and
etching said surface and the mesa therein
whereby a ridge is formed in the surface of
the substrate.
10. A method according to claim 8 or 9 wherein the substrate is composed of InP.
11. A method according to claim 8 or 9 wherein the portion of the surface of the substrate coated with an etch resistant material is in the form of a stripe on the surface of the substrate.
12. A semiconductor laser substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.
13. A method of making a semiconductor laser or substrate therefor, substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08230129A GB2129211B (en) | 1982-10-21 | 1982-10-21 | Semiconductor laser and a method of making same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08230129A GB2129211B (en) | 1982-10-21 | 1982-10-21 | Semiconductor laser and a method of making same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2129211A true GB2129211A (en) | 1984-05-10 |
| GB2129211B GB2129211B (en) | 1987-01-14 |
Family
ID=10533764
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08230129A Expired GB2129211B (en) | 1982-10-21 | 1982-10-21 | Semiconductor laser and a method of making same |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2129211B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1273284A (en) * | 1970-10-13 | 1972-05-03 | Standard Telephones Cables Ltd | Improvements in or relating to injection lasers |
| US4185256A (en) * | 1978-01-13 | 1980-01-22 | Xerox Corporation | Mode control of heterojunction injection lasers and method of fabrication |
| GB2027261A (en) * | 1978-07-31 | 1980-02-13 | Rca Corp | Semiconductor laser |
| US4215319A (en) * | 1979-01-17 | 1980-07-29 | Rca Corporation | Single filament semiconductor laser |
| GB1587008A (en) * | 1977-08-15 | 1981-03-25 | Ibm | Heterostructure junction laser |
| EP0026062A1 (en) * | 1979-09-12 | 1981-04-01 | Xerox Corporation | A heterojunction semiconductor laser |
| GB2062949A (en) * | 1979-10-12 | 1981-05-28 | Rca Corp | Single filament semiconductor laser with large emitting area |
-
1982
- 1982-10-21 GB GB08230129A patent/GB2129211B/en not_active Expired
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1273284A (en) * | 1970-10-13 | 1972-05-03 | Standard Telephones Cables Ltd | Improvements in or relating to injection lasers |
| GB1587008A (en) * | 1977-08-15 | 1981-03-25 | Ibm | Heterostructure junction laser |
| US4185256A (en) * | 1978-01-13 | 1980-01-22 | Xerox Corporation | Mode control of heterojunction injection lasers and method of fabrication |
| GB2027261A (en) * | 1978-07-31 | 1980-02-13 | Rca Corp | Semiconductor laser |
| US4215319A (en) * | 1979-01-17 | 1980-07-29 | Rca Corporation | Single filament semiconductor laser |
| EP0026062A1 (en) * | 1979-09-12 | 1981-04-01 | Xerox Corporation | A heterojunction semiconductor laser |
| GB2062949A (en) * | 1979-10-12 | 1981-05-28 | Rca Corp | Single filament semiconductor laser with large emitting area |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2129211B (en) | 1987-01-14 |
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| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20021020 |