Patent EP0401971A2 successfully refreshed from Google Patents.
EP0401971A2
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Optical waveguide and method for its manufacture
Assignee: Nortel Networks Ltd
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Filing: 1990-05-02
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Granted: —
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Expires: 2010-05-02
Abstract
Abstract An optical waveguide is made by forming a layer of SiO2 on a substrate and implanting a region of the SiO2 layer with Si ions to define a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index. The resulting optical waveguide is stable at the high temperatures required for many semiconductor processing methods, and is useful for optical interconnection in integrated optical and optoelectronic devices.
Inventors
- 👤 Alexander Kalnitsky
- 👤 Joseph Paul Ellul
- 👤 Albert Roy Boothroyd
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 12:45
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/134; G02B6/1347
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
45 words
An optical waveguide, comprising: a substrate; and a layer of SiO₂ on the substrate, the layer of SiO₂ comprising a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index.
Claim 2
Dependent Claim
45 words
An optical waveguide, comprising: a substrate; and a layer of SiO₂ on the substrate, the layer of SiO₂ comprising a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index.
Claim 3
Dependent Claim
20 words
An optical waveguide as defined in claim 1, wherein the stoichiometric excess of Si defines a graded refractive index profile.
Claim 4
Dependent Claim
24 words
An optical waveguide as defined in claim 2, wherein the stoichiometric excess of Si as a function of depth approximates a Gaussian distribution function.
Claim 5
Independent Claim
47 words
A method for making an optical waveguide, the method comprising: forming a layer of SiO₂ on a substrate; and implanting a region of the SiO₂ layer with Si ions to define a region having an elevated refractive index surrounded by a region having a lower refractive index.
Claim 6
Independent Claim
47 words
A method for making an optical waveguide, the method comprising: forming a layer of SiO₂ on a substrate; and implanting a region of the SiO₂ layer with Si ions to define a region having an elevated refractive index surrounded by a region having a lower refractive index.
Claim 7
Dependent Claim
29 words
A method as defined in claim 4, wherein the step of forming a layer of SiO₂ on a substrate comprises growing a layer of SiO₂ on a Si substrate.
Claim 8
Dependent Claim
33 words
A method as defined in claim 5, wherein the step of growing a layer of SiO₂ on a Si substrate comprises growing a layer of SiO₂ on the Si substrate by steam oxidation.
Claim 9
Dependent Claim
19 words
A method as defined in claim 6, wherein the steam oxidation is performed at a pressure exceeding atmospheric pressure.
Claim 10
Dependent Claim
32 words
A method as defined in claim 4, wherein the step of forming a layer of SiO₂ on a substrate comprises depositing a layer of SiO₂ on a substrate by chemical vapour deposition.
Claim 11
Dependent Claim
68 words
A method as defined in claim 4, wherein the step of implanting a region of the SiO₂ layer with Si ions comprises: forming an ion implantation mask over the SiO₂ layer, the ion implantation mask having openings therethrough over regions of the SiO₂ layer where implantation of Si ions is desired; and selectively implanting Si ions into the SiO₂ layer through the openings of the ion implantation mask.
Claim 12
Dependent Claim
47 words
A method as defined in claim 4, wherein the step of implanting a region of the SiO₂ layer with Si ions comprises implanting the Si ions with an implantation dose between 1x10¹⁴ cm⁻² and 2x10¹⁷ cm⁻² and with an implantation energy between 3 keV and 400 keV.
Claim 13
Dependent Claim
47 words
A method as defined in claim 4, further comprising: forming an oxidation-resistant mask over the regions of the implanted SiO₂ layer where a waveguide is desired; and heating the SiO₂ layer in an oxidizing ambient to oxidize the implanted Si in exposed regions of the SiO₂ layer.
Claim 14
Dependent Claim
25 words
A method as defined in claim 4, further comprising annealing the implanted SiO₂ layer at a temperature exceeding 1000 degrees Celsius in a non-oxidizing ambient.
Claim 15
Dependent Claim
25 words
A method as defined in claim 4, comprising performing a series of implantation steps at different implantation energies to define a non-Gaussian refractive index profile.
Claim 16
Dependent Claim
17 words
A method as defined in claim 13, wherein successive implantation steps are performed with different implantation doses.
Claim 17
Dependent Claim
17 words
A method as defined in claim 14, wherein successive implantation steps are performed through different implantation masks.
References Cited (Backward Citations)
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