US4206251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for diffusing metals into substrates
Assignee: Raytheon Co
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Filing: 1978-06-01
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Granted: 1980-06-03
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Expires: 1998-06-01
Abstract
Abstract The specification describes a process for diffusing a metal into a substrate which may be either a semiconductor material or a dielectric material. The substrate is first coated with a liquid composition comprising organo-metallic solutions of the desired metal and silica. The coated substrate is then heated at an elevated temperature for a period of time sufficient to cause the organic portion of the solution to decompose, thereby leaving a composite film comprising an oxide of the desired metal and SiO 2 . Upon further heating, the metal from the metal oxide diffuses into the substrate. The residual composite film may be left in place or removed.
Inventors
- 👤 Bor-Uei Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:52
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/134; G02B6/1342; C; C23; C23C; C23C10/00; C23C10/28; C30; C30B; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/30; C30B31/00; C30B31/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
A process for forming an optical waveguide in a dielectric substrate selected from the group consisting of lithium niobate and lithium tantalate while simultaneously suppressing the out-diffusion of lithium oxide from said substrate, comprising the steps of: (a) providing an organo-metallic solution including titanium and silicon; (b) applying said solution to said dielectric substrate to form an organo-metallic film thereon; and (c) heating said substrate and film thereon to a chosen elevated temperature for a period of time sufficient to form a composite film comprising titanium oxide and silicon dioxide and to diffuse said titanium from said titanium oxide into said substrate to form a titanium-diffused waveguiding layer in said substrate and to suppress the out-diffusion of lithium oxide from said substrate with said composite film, whereby the optical waveguiding and propagation characteristics of said waveguiding layer are enhanced.
Claim 2
Dependent Claim
139 words
A process for forming an optical waveguide in a dielectric substrate selected from the group consisting of lithium niobate and lithium tantalate while simultaneously suppressing the out-diffusion of lithium oxide from said substrate, comprising the steps of: (a) providing an organo-metallic solution including titanium and silicon; (b) applying said solution to said dielectric substrate to form an organo-metallic film thereon; and (c) heating said substrate and film thereon to a chosen elevated temperature for a period of time sufficient to form a composite film comprising titanium oxide and silicon dioxide and to diffuse said titanium from said titanium oxide into said substrate to form a titanium-diffused waveguiding layer in said substrate and to suppress the out-diffusion of lithium oxide from said substrate with said composite film, whereby the optical waveguiding and propagation characteristics of said waveguiding layer are enhanced.
Claim 3
Dependent Claim
82 words
A process for forming titanium waveguiding layers in lithium niobate, LiNbO 3 , which includes depositing an organo-metallic solution of chosen amounts of titanium, Ti, and silica, SiO 2 , on the surface of a lithium niobate substrate and thereafter thermally decomposing the organo-metallic film resulting from said solution to diffuse the titanium therefrom into said substrate to form a thin titanium waveguiding layer therein, whereby Li 2 O out-diffusion from said substrate is prevented by the presence of said organo-metallic film.
Claim 4
Dependent Claim
82 words
A process for forming titanium waveguiding layers in lithium niobate, LiNbO 3 , which includes depositing an organo-metallic solution of chosen amounts of titanium, Ti, and silica, SiO 2 , on the surface of a lithium niobate substrate and thereafter thermally decomposing the organo-metallic film resulting from said solution to diffuse the titanium therefrom into said substrate to form a thin titanium waveguiding layer therein, whereby Li 2 O out-diffusion from said substrate is prevented by the presence of said organo-metallic film.
Claim 5
Independent Claim
86 words
A method for forming a single mode optical waveguide in LiNbO 3 crystals which includes coating a sample of said crystal with an organo-metallic titanium-silica film and heating said sample at an elevated temperature for a period of time sufficient to form a composite film comprising TiO 2 and SiO 2 and to cause Ti diffusion into said crystal to occur, whereby Ti from said TiO 2 diffuses into said crystal and Li 2 O diffusion out of said crystal is prevented by said composite film.
Claim 6
Independent Claim
86 words
A method for forming a single mode optical waveguide in LiNbO 3 crystals which includes coating a sample of said crystal with an organo-metallic titanium-silica film and heating said sample at an elevated temperature for a period of time sufficient to form a composite film comprising TiO 2 and SiO 2 and to cause Ti diffusion into said crystal to occur, whereby Ti from said TiO 2 diffuses into said crystal and Li 2 O diffusion out of said crystal is prevented by said composite film.
Claim 7
Dependent Claim
33 words
A method as set forth in claim 3 wherein said heating is performed first at 600° C. for 4 hours and then at 900° C. for 16 hours in a flowing oxygen atmosphere.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |