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Patent US6063299A successfully refreshed from Google Patents.
US6063299A
Expired / Lapsed
US
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Manufacture of a silicon waveguide structure
Assignee: Lumentum Technology UK Ltd
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Filing: 1999-01-13
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Granted: 2000-05-16
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Expires: 2019-01-13
Abstract
Abstract A process for making a silicon rib wavegide structure is described comporising the following steps: (i) forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface; (ii) depositing a buffer layer at least over said exposed surface; (iii) carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and (iv) forming a layer of cladding at least on side walls of the silicon rib.
Inventors
- 👤 John Paul Drake
- 👤 Matthew Peter Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:36
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/136; G02B6/122; G02B6/126; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/025
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A process for making a silicon rib waveguide structure comprising: forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface; depositing a buffer layer at least over said exposed surface; carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and forming a layer of cladding at least on side walls of the silicon rib.
Claim 2
Dependent Claim
87 words
A process for making a silicon rib waveguide structure comprising: forming a window in a protective layer on the surface of a silicon wafer to expose a part of said surface; depositing a buffer layer at least over said exposed surface; carrying out an etch step to etch the buffer layer and silicon outside a protected rib portion thereby to form a silicon rib with the buffer layer on its upper surface; and forming a layer of cladding at least on side walls of the silicon rib.
Claim 3
Dependent Claim
13 words
A process according to claim 1, wherein the buffer layer comprises silicon nitride.
Claim 4
Dependent Claim
16 words
A process according to claim 2, wherein the buffer layer is deposited using an LPCVD process.
Claim 5
Dependent Claim
14 words
A process according to claim 1, wherein the buffer layer is a native oxide.
Claim 6
Dependent Claim
26 words
A process according to claim 1, wherein the thickness of the buffer layer is in the range 20-500 Å and preferably in the range 80-220 Å.
Claim 7
Dependent Claim
25 words
A process according to claim 1, which further comprises the step of forming a light absorbing layer on the buffer layer to define a polariser.
Claim 8
Dependent Claim
38 words
A process according to claim 1, wherein the step of forming a layer of cladding comprises carrying out an oxidation step such that a cladding layer of oxide is formed on the side walls of the silicon rib.
Claim 9
Dependent Claim
18 words
A process according to claim 1, wherein the cladding layer and the buffer layer have different etch characteristics.
Claim 10
Dependent Claim
55 words
A process according to claim 1, which further comprises selectively removing either the buffer layer from the top surface of the rib or the cladding layer from at least one of the side walls of the rib, and introducing dopants into the area from which the buffer layer or cladding layer respectively has been removed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-16 | 2003-11-15 | 2004-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-16 | 2007-11-15 | 2008-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-16 | 2011-11-15 | 2012-05-16 | $7700.00 | Window Closed / Lapsed |