EP0187662A2
Expired / Lapsed
EP
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Monolithically integrated semiconductor optical device and method of fabricating same
Assignee: NEC Corp
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Filing: 1986-01-08
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Granted: —
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Expires: 2006-01-08
Abstract
Abstract In monolithically integrating at least two semiconductor optical devices such as, e.g., a combination of a DFB laser (50) and a light modulator (60) by using multilayer semiconductor structure including an active layer (14) of stripe form, a mesa stripe (40) which lengthwise incorportes a portion of the active stripe is formed between and contiguous to adjacent two optical devices. The mesa stripe (40) has neither electrode nor contact layer, and the multilayer structure is partially removed to expose a layer directly beneath the active layer (14). By this construction electrical insulation between the optical devices becomes sufficient while optical connection is established by the active stripe in the mesa stripe (40). The mesa stripe (40) can easily be formed by initially preparing the multilayer semiconductor structure with a channel-like depression (29) in the uppermost layer so as to extend above and parallel to the active stripe (14), once filling up the depression (29) with a portion of a contact layer (30), and etching unnecessary regions of the multilayer semiconductor structure by using the contact layer (30) in the depression (29) as a mask.
Inventors
- 👤 Masayuki Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 03:26
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/227; H01S5/02; H01S5/026; H01S5/0265; H01S5/10; H01S5/12; H01S5/06; H01S5/062; H01S5/0625; H01S5/2275; H01S5/2277
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
134 words
A monolithically integrated semiconductor optical device, comprising a body of a multilayer semiconductor structure including an active layer which is in the form of a stripe and has the function of emitting, absorbing or waveguiding light, said body comprising at least two functional regions, which are arranged distant from each other such that said stripe extends in each of said at least two functional regions and each of which has an electrode on its outermost layer, and a mesa stripe which is formed between and contiguous to said at least two functional regions and,lengthwise incorporates a portion of said active layer in the form of said stripe, said multilayer semiconductor structure being partially removed such that a semiconductor layer directly beneath said active layer is exposed in regions sideways contiguous to said mesa stripe.
Claim 2
Dependent Claim
134 words
A monolithically integrated semiconductor optical device, comprising a body of a multilayer semiconductor structure including an active layer which is in the form of a stripe and has the function of emitting, absorbing or waveguiding light, said body comprising at least two functional regions, which are arranged distant from each other such that said stripe extends in each of said at least two functional regions and each of which has an electrode on its outermost layer, and a mesa stripe which is formed between and contiguous to said at least two functional regions and,lengthwise incorporates a portion of said active layer in the form of said stripe, said multilayer semiconductor structure being partially removed such that a semiconductor layer directly beneath said active layer is exposed in regions sideways contiguous to said mesa stripe.
Claim 3
Dependent Claim
23 words
An integrated semiconductor optical device according to Claim 1, wherein one of said at least two functional regions operates as a semiconductor laser.
Claim 4
Dependent Claim
20 words
A device according to Claim 2, wherein another of said at least two functional regions operates as a light modulator.
Claim 5
Dependent Claim
16 words
A device according to Claim 2, wherein said semiconductor laser is a distributed feed-back laser diode.
Claim 6
Dependent Claim
14 words
A device according to Claim 2, wherein said semiconductor laser is of a planar-buried-heterostructure.
Claim 7
Dependent Claim
14 words
A device according to Claim 5, wherein said semiconductor laser is of a double-channel-planar-buried-heterostructure.
Claim 8
Independent Claim
21 words
A device according to any of Claims 1 to 6, wherein said multilayer semiconductor structure is formed of InP and InGaAsP.
Claim 9
Independent Claim
21 words
A device according to any of Claims 1 to 6, herein said multilayer semiconductor structure is formed of GaAs and AlGaAs.
Claim 10
Independent Claim
225 words
A method of fabricating a monolithically integrated semiconductor optical device according to Claim l, the method comprising the steps of: (a) preparing a body of a multilayer semiconductor structure, which includes an active layer in the form of a stripe, such that an uppermost layer thereof is formed with a channel-like depression which extends above and parallel to said stripe; (b) overlaying said uppermost layer with a contact layer different in material from said uppermost layer so as to fill up said depression and so as to provide a flat upper surface; (c) forming at least two separate electrodes on said contact layer so as to be spaced from each other in the longitudinal direction of said stripe; (d) etching said contact layer in every region intervening between said at least two electrodes so as to leave said contact layer unremoved only in said depression; (e) etching said multilayer semiconductor structure in every region between said at least two electrodes by using said contact layer remaining in said depression as an etching mask so as to form a mesa stripe with its top face covered with said contact layer remaining in said depression and so as to expose a semiconductor layer directly beneath said active layer in regions sideways contiguous to said mesa stripe; and (f) removing said contact layer remaining on said mesa stripe.
Claim 11
Dependent Claim
157 words
A method according to Claim 9, wherein the step (a) comprises the sub-steps of: (i) preparing a multilayer semiconductor wafer comprising an active layer formed on a buffer layer and a light guide layer which is formed on said active layer and is overlaid with a flat cladding layer; (ii) forming two parallel channels each of which reaches from the upper surface of said cladding layer to said buffer layer to thereby provide a mesa stripe including said active region in the form of a stripe between said two channels; (iii) forming blocking layers on said channels and on said cladding layer except the upper surface of the mesa stripe formed at sub-step (i); (iv) forming an embedding layer on said blocking layers and also on the upper surface of the mesa stripe formed at sub-step (i) such that the upper surface of said embedding layer has said depression above the mesa stripe formed at sub-step (i).
Claim 12
Dependent Claim
36 words
ll. A method according to Claim 10, wherein a diffraction grating is formed in said light guide layer only in a selected region above which one of said at least two electrodes is to be formed.
Claim 13
Independent Claim
21 words
A method according to any of Claims 9 to 11, wnerein said multilayer semiconductor structure is formed of InP and InGaAsP.
Claim 14
Independent Claim
21 words
A method according to any of Claims 9 to 11, wherein said multilayer semiconductor structure is formed of GaAs and AlGaAs.
References Cited (Backward Citations)
No citation records indexed.
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