US4764246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Buried undercut mesa-like waveguide and method of making same
Assignee: Nokia Bell Labs
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Filing: 1987-08-20
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Granted: 1988-08-16
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Expires: 2007-08-20
Abstract
Abstract Epitaxial regrowth by vapor phase epitaxy of controlled composition semiconductor material in and around undercut regions of a processed heterostructure wafer permits formation of a ridge waveguide capable of active or passive operation. Subsequent material selective and crystallographically preferential etching is employed to form mirror facets on each end of the ridge waveguide.
Inventors
- 👤 Thomas J. Bridges
- 👤 Ernest G. Burkhardt
- 👤 Larry A. Coldren
- 👤 Thomas L. Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:03
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/131; H; H01; H01S; H01S5/00; H01S5/20; H01S5/24; H01S5/2054; H01S5/2081; H01S5/22; H01S5/223; H01S5/2237; H01S5/227; H01S5/2275
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
A method of fabricating a device comprising a buried undercut region comprising the steps of: growing a semiconductor heterostructure, said heterostructure comprising at least two layers of which at least one is a buried layer; using a material selective etchant to remove a portion of said at least one buried layer thereby forming an undercut region under at least one layer of said heterostructure; and regrowing said undercut region by a vapor phase epitaxial growth technique.
Claim 2
Independent Claim
76 words
A method of fabricating a device comprising a buried undercut region comprising the steps of: growing a semiconductor heterostructure, said heterostructure comprising at least two layers of which at least one is a buried layer; using a material selective etchant to remove a portion of said at least one buried layer thereby forming an undercut region under at least one layer of said heterostructure; and regrowing said undercut region by a vapor phase epitaxial growth technique.
Claim 3
Dependent Claim
23 words
A method as recited in claim 1 further comprising the step of removing a portion of said regrown material to form mirror facets.
Claim 4
Dependent Claim
19 words
A method as recited in claim 1 in which said at least one buried layer has a long axis.
Claim 5
Dependent Claim
25 words
A method as recited in claim 3 in which said undercut region is parallel to the long axis of said at least one buried layer.
Claim 6
Dependent Claim
25 words
A method as recited in claim 3 in which said undercut region is perpendicular to the long axis of said at least one buried layer.
Claim 7
Dependent Claim
19 words
A method as recited in claim 1 in which said regrowing is at a temperature below 650 degrees C.
Claim 8
Dependent Claim
19 words
A method as recited in claim 2 further comprising the step of forming a mesa prior to said etching.
Claim 9
Dependent Claim
15 words
A method as recited in claim 7 which said regrowing forms a high resistivity region.
Claim 10
Dependent Claim
15 words
A method as recited in claim 7 comprising the further step of adding electrical contacts.
Claim 11
Dependent Claim
14 words
A method as recited in claim 1 in which two undercut regions are formed.
Claim 12
Dependent Claim
16 words
A method as recited in claim 10 in which said two undercut regions are mutually orthogonal.
References Cited (Backward Citations)
US3833435A
Cited
US3883219A
Cited
US4099305A
Cited
US4285763A
Cited
US4468850A
Cited
US4662988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |