US5473624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser system and method for selectively severing links
Assignee: Electro Scientific Industries Inc
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Filing: 1994-11-22
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Granted: 1995-12-05
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Expires: 2014-11-22
Abstract
Abstract A laser system and processing method exploits the absorption contrast between the materials from which a link (12) and an underlying substrate (22) are made to effectively remove the link from the substrate. Laser output in a wavelength range of 1.2 to 3 μm (30) optimizes the absorption contrast between many materials (e.g., metals, polysilicon, polycides, or disilicides) and integrated circuit substrates (e.g., silicon, gallium arsenide, or other semiconductors) and permits the use of laser output in a wider range of energy or power levels, pulse widths, and spot sizes without risking damage to the substrates or adjacent circuit structures. Existing link processing laser systems can be readily modified to operate in the 1.2 to 3 μm range.
Inventors
- 👤 Yunlong Sun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:03
CPC Classifications
B; B23; B23K; B23K26/00; B23K26/02; B23K26/06; B23K26/064; B23K26/0643; B23K26/351; B23K26/36; B23K26/361; B23K26/40; H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/067; H10W20/068; B23K2101/00; B23K2101/34; B23K2103/00; B23K2103/08; B23K2103/10; B23K2103/12; B23K2103/14; B23K2103/16; B23K2103/166; B23K2103/172; B23K2103/18; B23K2103/26; B23K2103/50; H01; H01S; H01S3/00; H01S3/02; H01S3/025; H01S3/04; H01S3/0401; H01S3/09; H01S3/091; H01S3/094; H01S3/0941; H01S3/09415; H01S3/10; H01S3/11; H01S3/1123; H01S3/14; H01S3/16; H01S3/1601; H01S3/1603; H01S3/1611; H01S3/163; H01S3/1645; H01S3/1653; Y; Y10; Y10S; Y10S438/00; Y10S438/94
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
121 words
A method for selectively processing a multilayer, multimaterial device that includes a substrate and a nonmetal target structure having respective first and second wavelength-sensitive light absorption characteristics, the first and second absorption characteristics having different light absorption properties that provide different light absorption contrasts for different wavelengths of light, comprising: generating at a predetermined wavelength a laser output having a predetermined spatial spot size; and directing the laser output to illuminate the nonmetal target structure, the predetermined wavelength providing a sufficiently large absorption contrast between the nonmetal target structure and the substrate to change a physical property of the nonmetal target structure but leave substantially unchanged the physical property of the substrate within the spatial spot size of the laser output.
Claim 2
Independent Claim
121 words
A method for selectively processing a multilayer, multimaterial device that includes a substrate and a nonmetal target structure having respective first and second wavelength-sensitive light absorption characteristics, the first and second absorption characteristics having different light absorption properties that provide different light absorption contrasts for different wavelengths of light, comprising: generating at a predetermined wavelength a laser output having a predetermined spatial spot size; and directing the laser output to illuminate the nonmetal target structure, the predetermined wavelength providing a sufficiently large absorption contrast between the nonmetal target structure and the substrate to change a physical property of the nonmetal target structure but leave substantially unchanged the physical property of the substrate within the spatial spot size of the laser output.
Claim 3
Dependent Claim
17 words
The method of claim 1 in which the substrate comprises silicon, gallium arsenide, or other semiconductor materials.
Claim 4
Dependent Claim
18 words
The method of claim 2 in which the nonmetal target structure comprises doped polysilicon, polycide, or disilicide material.
Claim 5
Dependent Claim
22 words
The method of claim 1 in which the wavelength of the laser output is in about the 1.2 to 3 μm range.
Claim 6
Dependent Claim
26 words
The method of claim 1 in which the nonmetal target structure has a width that is smaller than the spatial spot size of the laser output.
Claim 7
Dependent Claim
32 words
The method of claim 1 in which the nonmetal target structure comprises multiple layers and the laser output comprises energy in excess of that which is required to process the nonmetal structure.
Claim 8
Dependent Claim
17 words
The method of claim 1 in which the laser output is generated by a Q-switched, solid-state laser.
Claim 9
Dependent Claim
18 words
The method of claim 1 in which the nonmetal target structure comprises doped polysilicon, polycide, or disilicide material.
Claim 10
Dependent Claim
105 words
A laser system for selectively processing a nonmetal target structure of a multilayer, multimaterial device including a substrate, the nonmetal target structure and substrate having wavelength-sensitive properties, comprising: a pumping source; and a lasant positioned in a resonator cavity adapted to be pumped by the pumping source to provide a laser output having a spatial spot size, power, and wavelength selected to exploit differences in the wavelength-sensitive properties of the nonmetal target structure and the substrate such that the nonmetal target structure within the spatial spot size is effectively processed and the substrate within the spatial spot size is relatively undamaged by the laser output.
Claim 11
Dependent Claim
105 words
A laser system for selectively processing a nonmetal target structure of a multilayer, multimaterial device including a substrate, the nonmetal target structure and substrate having wavelength-sensitive properties, comprising: a pumping source; and a lasant positioned in a resonator cavity adapted to be pumped by the pumping source to provide a laser output having a spatial spot size, power, and wavelength selected to exploit differences in the wavelength-sensitive properties of the nonmetal target structure and the substrate such that the nonmetal target structure within the spatial spot size is effectively processed and the substrate within the spatial spot size is relatively undamaged by the laser output.
Claim 12
Dependent Claim
18 words
The laser system of claim 9 in which the substrate comprises silicon, gallium arsenide, or other semiconductor materials.
Claim 13
Dependent Claim
23 words
The laser system of claim 9 in which the wavelength of the laser output is in about the 1.2 to 3 μm range.
Claim 14
Dependent Claim
26 words
The laser system of claim 9 in which the nonmetal target structure has a width that is smaller than the critical dimensions of the laser output.
Claim 15
Dependent Claim
34 words
The laser system of claim 9 in which the nonmetal target structure comprises multiple layers and the laser output comprises energy in excess of that which is required to process the nonmetal target structure.
Claim 16
Dependent Claim
16 words
The laser system of claim 9 further comprising a Q-switched, diode-pumped or arc-lamp pumped, solid-state laser.
Claim 17
Dependent Claim
55 words
The laser system of claim 9 in which the lasant is selected from the group of Nd:YAG, Nd:YLF, Nd:YAP, and Nd:YVO 4 and in which the resonator cavity employs resonator mirrors that are highly transmissive to a conventional wavelength of the lasant but have desired reflectivity within a wavelength range of 1.2 to 3 μm.
Claim 18
Dependent Claim
43 words
The laser system of claim 9 in which the lasant comprises YAG doped with holmium or erbium, or codoped with chromium, thulium, and holmium, and the resonator cavity is adapted to generate laser output within a wavelength range of 1.2 to 3 μm.
Claim 19
Dependent Claim
26 words
The laser system of claim 9 in which non-linear frequency conversion is adapted to generate laser output within a wavelength range of 1.2 to 3 μm.
Claim 20
Dependent Claim
19 words
The laser system of claim 9 in which the nonmetal target structure comprises doped polysilison, polycide, or disilicide material.
Claim 21
Independent Claim
58 words
A method for employing a laser system to process nonmetal link structures formed on a silicon, gallium arsenide, or other semiconductor substrate, comprising: generating laser output in a wavelength range of about 1.2 to 3 μm; and directing the laser output at the nonmetal link structure such that it is effectively processed but the substrate is relatively undamaged.
Claim 22
Independent Claim
58 words
A method for employing a laser system to process nonmetal link structures formed on a silicon, gallium arsenide, or other semiconductor substrate, comprising: generating laser output in a wavelength range of about 1.2 to 3 μm; and directing the laser output at the nonmetal link structure such that it is effectively processed but the substrate is relatively undamaged.
Claim 23
Dependent Claim
33 words
The method of claim 19 in which the nonmetal link structure comprises multiple layers and the laser output comprises energy in excess of that which is required to process the nonmetal link structure.
Claim 24
Dependent Claim
19 words
The laser system of claim 19 in which the nonmetal link structure comprises doped polysilison, polycide, or disilicide material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-12-04 | 1999-06-05 | 1999-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-04 | 2003-06-05 | 2003-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-04 | 2007-06-05 | 2007-12-05 | $7700.00 | Window Closed / Lapsed |