US5322988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser texturing
Assignee: United States Department of the Navy
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Filing: 1992-07-27
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Granted: 1994-06-21
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Expires: 2012-07-27
Abstract
Abstract A non-contact method to impart a texture to a surface using laser irradian uses an excimer laser to illuminate a sample immersed in a halocarbon ambient thereby initiating a photo/thermal chemical reaction which etches the sample only in the area illuminated with sufficient laser fluence. The resulting etched area can be repetively illuminated and etched to provide a textured surface to reduce extraneous reflections, or for micromachining, decorative texturing and marking. This technique is particularly well suited to improve the performance of backside illuminated CCDs by reducing the background (dark) signal, increase resolution and responsivity uniformity. The technique is compatible with other laser processing procedures and can be implemented with a variety of CCD enhancements such as improved dark current and blue response from laser doping or activation of backside implants. The noncorrosive nature of the halocarbon ambients allows the laser texturing process to be performed on pre-packaged, pre-tested devices and therefore can salvage parts which had failed performance specifications. This process therefore can improve device performance as well as yield, reliability and fabrication costs.
Inventors
- 👤 Stephen D. Russell
- 👤 Douglas A. Sexton
- 👤 Eugene P. Kelley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:39
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; B; B01; B01D; B01D53/00; B01D53/007; B01J; B01J19/00; B01J19/08; B01J19/12; B01J19/121; H10F; H10F77/00; H10F77/70; H10F77/703; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A method of texturing a surface of a sample using laser-assisted etching in a gaseous chlorofluorocarbon ambient comprising: placing said surface of said sample in contact with said gaseous chlorofluorocarbon ambient; directing a laser beam onto said surface of said sample to at least partially directly transfer radiant energy onto said sample within said gaseous chlorofluorocarbon ambient to create melted portions of said surface of said sample where the radiant energy of the laser beam impinges; and etching away only said melted portions of said surface of said sample within said gaseous chlorofluorocarbon ambient which have said radiant energy impinging thereon.
Claim 2
Independent Claim
101 words
A method of texturing a surface of a sample using laser-assisted etching in a gaseous chlorofluorocarbon ambient comprising: placing said surface of said sample in contact with said gaseous chlorofluorocarbon ambient; directing a laser beam onto said surface of said sample to at least partially directly transfer radiant energy onto said sample within said gaseous chlorofluorocarbon ambient to create melted portions of said surface of said sample where the radiant energy of the laser beam impinges; and etching away only said melted portions of said surface of said sample within said gaseous chlorofluorocarbon ambient which have said radiant energy impinging thereon.
Claim 3
Dependent Claim
20 words
A method according to claim 1 in which said radiant energy is a UV wavelength beam coming from a laser.
Claim 4
Dependent Claim
53 words
A method according to claim 2 in which said surface of said sample is placed within a processing chamber and said chlorofluorocarbon ambient is pressurized within predetermined limits and said UV wavelength beam is at predetermined rates and intensities to assure that said surface of said sample is melted but not ablated thereby.
Claim 5
Dependent Claim
31 words
A method according to claim 3 in which said UV wavelength beam is shaped, homogenized and adjusted in magnitude to obtain an optimal fluence impinging onto said surface of said sample.
Claim 6
Dependent Claim
19 words
A method according to claim 4 in which the pressure of said chlorofluorocarbon ambient is greater than 150 torr.
Claim 7
Dependent Claim
38 words
A method according to claim 5 in which the pressure of said chlorofluorocarbon ambient is between 600 and 900 torr and incident fluence of said UV wavelength beam is between 0.75 J/cm 2 and 2.0 J/cm 2 .
Claim 8
Dependent Claim
15 words
A method according to claim 5 or 6 in which the chlorofluorocarbon ambient is chloropentafluoroethane.
Claim 9
Dependent Claim
20 words
A method according to claim 1, 2, 3, 4, 5, or 6, in which said sample is an elemental semiconductor.
Claim 10
Dependent Claim
29 words
A method according to claim 1, 2, 3, 4, 5 or 6 in which said sample is selected from the materials groups consisting of compound semiconductors, ceramics and metals.
Claim 11
Independent Claim
112 words
A method of laser-assisted texturing of a surface of a sample in a gaseous halocarbon ambient comprising: placing said surface of said sample in contact with said gaseous halocarbon ambient; directing a laser beam onto said surface of said sample to at least partially directly transfer radiant energy onto said surface of said sample within said gaseous halocarbon ambient to create melted portions in a textured pattern of said surface of said sample where the radiant energy of the laser beam impinges; and etching away only said melted portions of said surface of said sample within said gaseous halocarbon ambient which have said radiant energy impinging thereon thereby effecting the texturing thereof.
Claim 12
Independent Claim
112 words
A method of laser-assisted texturing of a surface of a sample in a gaseous halocarbon ambient comprising: placing said surface of said sample in contact with said gaseous halocarbon ambient; directing a laser beam onto said surface of said sample to at least partially directly transfer radiant energy onto said surface of said sample within said gaseous halocarbon ambient to create melted portions in a textured pattern of said surface of said sample where the radiant energy of the laser beam impinges; and etching away only said melted portions of said surface of said sample within said gaseous halocarbon ambient which have said radiant energy impinging thereon thereby effecting the texturing thereof.
Claim 13
Dependent Claim
20 words
A method according to claim 10 in which said radiant energy is a UV wavelength beam coming from a laser.
Claim 14
Dependent Claim
50 words
A method according to claim 11 in which said surface of said sample is placed within a processing chamber and said halocarbon ambient is pressurized within predetermined limits and said UV wavelength beam is at predetermined rates and intensities to assure that said sample is melted but not ablated thereby.
Claim 15
Dependent Claim
18 words
A method according to claim 12 in which the UV wavelength beam is emitted from an excimer laser.
Claim 16
Dependent Claim
18 words
A method according to claim 10, 11, 12 or 13 in which said sample is an elemental semiconductor.
Claim 17
Dependent Claim
27 words
A method according to claim 10, 11, 12 or 13 in which said sample is selected from the materials group consisting of compound semiconductors, ceramics and metals.
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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) | 1997-06-20 | 1997-12-20 | 1998-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-20 | 2001-12-20 | 2002-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-20 | 2005-12-20 | 2006-06-21 | $7700.00 | Window Closed / Lapsed |