US4415373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser process for gettering defects in semiconductor devices
Assignee: Honeywell International Inc
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Filing: 1981-11-17
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Granted: 1983-11-15
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Expires: 2001-11-17
Abstract
Abstract A process for gettering defects in a semiconductor is provided. The process comprises using a laser beam to drive a dopant material into a melted non-active surface of a semiconductor device, followed by heating the semiconductor to drive defects to traps formed by the dopant. The process creates in the bulk of the semiconductor strain fields that not only trap defects, which would otherwise degrade device performance, but also hold the defects during subsequent processing steps.
Inventors
- 👤 Robert J. Pressley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:32
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; H10P34/00; H10P34/40; H10P34/42; H10P36/00; H10P36/03; Y; Y10; Y10S; Y10S148/00; Y10S148/093
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
A process for gettering defects in a semiconductor wafer comprising the steps of: (a) providing a dopant material at a major surface of the wafer, that surface being opposite to a second surface of the wafer in which a semiconductor device is formed; (b) generating a laser beam at a wavelength that is absorbed by the major surface; (c) directing the beam onto the major surface to melt the area of incidence and to diffuse the dopant into the wafer; and (d) heating the wafer at a temperature and for a time sufficient to drive defects to traps formed by the dopant in the wafer.
Claim 2
Dependent Claim
105 words
A process for gettering defects in a semiconductor wafer comprising the steps of: (a) providing a dopant material at a major surface of the wafer, that surface being opposite to a second surface of the wafer in which a semiconductor device is formed; (b) generating a laser beam at a wavelength that is absorbed by the major surface; (c) directing the beam onto the major surface to melt the area of incidence and to diffuse the dopant into the wafer; and (d) heating the wafer at a temperature and for a time sufficient to drive defects to traps formed by the dopant in the wafer.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein the dopant material is provided to the surface by applying to the surface a liquid that incorporates the dopant and then spinning the surface.
Claim 4
Dependent Claim
17 words
The process of claim 1 wherein the dopant material is provided to the surface by vapor deposition.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein the dopant material comprises an element selected from the group consisting of boron, arsenic, tin, tungsten, and molybdenum.
Claim 6
Dependent Claim
10 words
The process of claim 1 wherein the semiconductor comprises silicon.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein the laser beam is provided by an alexandrite laser.
Claim 8
Dependent Claim
31 words
The process of claim 1 comprising the further step of homogenizing the laser beam prior to step (c) so that the beam incident on the surface has substantially uniform power density.
Claim 9
Dependent Claim
38 words
The process of claim 1 comprising the further step of concentrating the laser beam prior to step (c) so that the beam incident on the surface is a narrow rectangular area of uniform power density along its length.
Claim 10
Dependent Claim
33 words
The process of claim 1 wherein the laser beam comprises a series of pulses and the surface is moved relative to the beam to provide a plurality of sequential exposures of the surface.
Claim 11
Dependent Claim
12 words
The process of claim 4 wherein the dopant comprises tungsten or molybdenum.
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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) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |