US4838989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser-driven fusion etching process
Assignee: United States Department of Energy
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Filing: 1987-08-25
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Granted: 1989-06-13
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Expires: 2007-08-25
Abstract
Abstract The surfaces of solid ionic substrates are etched by a radiation-driven chemical reaction. The process involves exposing an ionic substrate coated with a layer of a reactant material on its surface to radiation, e.g. a laser, to induce localized melting of the substrate which results in the occurrance of a fusion reaction between the substrate and coating material. The resultant reaction product and excess reactant salt are then removed from the surface of the substrate with a solvent which is relatively inert towards the substrate. The laser-driven chemical etching process is especially suitable for etching ionic salt substrates, e.g., a solid inorganic salt such as LiNbO3, such as used in electro-optical/acousto-optic devices. It is also suitable for applications wherein the etching process is required to produce an etched ionic substrate having a smooth surface morphology or when a very rapid etching rate is desired.
Inventors
- 👤 Carol I. H. Ashby
- 👤 Paul J. Brannon
- 👤 James B. Gerardo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:14
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/5346; C04B41/80; C04B41/91; C23; C23F; C23F1/00; C23F1/02; G; G02; G02B; G02B6/00; G02B6/24; G02B6/245
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
114 words
A process for etching a solid ionic substrate comprising: (a) applying a layer of coating material to a surface of said substrate, said coating material capable of reacting with said substrate when said substrate is in molten form, (b) selectively irradiating regions of said substrate surface to melt at least a portion of said substrate and form a fusion reaction product at the irradiated regions, and (c) removing said fusion reaction product and any excess coating material from said surface of said substrate by dissolving said fusion reaction product and said excess coating material with a solvent which does not substantially dissolve said substrate to thereby form an etched pattern in said substrate surface.
Claim 2
Dependent Claim
114 words
A process for etching a solid ionic substrate comprising: (a) applying a layer of coating material to a surface of said substrate, said coating material capable of reacting with said substrate when said substrate is in molten form, (b) selectively irradiating regions of said substrate surface to melt at least a portion of said substrate and form a fusion reaction product at the irradiated regions, and (c) removing said fusion reaction product and any excess coating material from said surface of said substrate by dissolving said fusion reaction product and said excess coating material with a solvent which does not substantially dissolve said substrate to thereby form an etched pattern in said substrate surface.
Claim 3
Dependent Claim
16 words
A process according to claim 1, wherein said substrate in LiNbO 3 or LiTaO 3 .
Claim 4
Dependent Claim
18 words
A process according to claim 1, wherein said coating material is a halide salt or a hydroxide salt.
Claim 5
Dependent Claim
20 words
A process according to claim 1, wherein said substrate is LiNbO 3 and said coating material is a fluoride salt.
Claim 6
Dependent Claim
12 words
A process according to claim 4, wherein said coating material is KF.
Claim 7
Dependent Claim
33 words
A process according to claim 5, wherein the source of radiation is a laser and the wavelength of light from said laser used to melt said substrate is less than about 310 nm.
Claim 8
Dependent Claim
20 words
A process according to claim 6, wherein said wavelength of light used to melt said substrate is about 270 nm.
Claim 9
Dependent Claim
27 words
A process according to claim 5, wherein said fusion reaction product and any excess KF from the surface of said substrate are removed by dissolution in water.
Claim 10
Dependent Claim
30 words
A process according to claim 1, wherein said coating material has a transparency of at least about 50% with respect to the wavelength of radiation used for melting said substate.
Claim 11
Dependent Claim
31 words
A process according to claim 1, wherein said fusion reaction product has a transparency of at least about 50% with respect to the wavelength of radiation used for melting said substrate.
Claim 12
Dependent Claim
34 words
A process according to claim 1, wherein the surface of said substrate has an absorbance of at least about 10 4 /cm with respect to the wavelength of radiation used for melting said substrate.
Claim 13
Dependent Claim
14 words
A process according to claim 1, wherein the source of radiation is a laser.
Claim 14
Dependent Claim
13 words
A process according to claim 12, wherein said laser is a pulsed laser.
Claim 15
Dependent Claim
28 words
A process according to claim 9, wherein said substrate is LiNbO 3 and the power deposition of said laser is at least about 10 6 W/cm 2 .
Claim 16
Dependent Claim
20 words
A process according to claim 1, wherein said coating material and said substrate are exposed to radiation through a mask.
Claim 17
Dependent Claim
14 words
A process according to claim 1, wherein said process is performed under ambient conditions.
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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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |