US4292576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mask-slice alignment method
Assignee: United States Department of the Air Force
•
Filing: 1980-02-29
•
Granted: 1981-09-29
•
Expires: 2000-02-29
Abstract
Abstract A method of aligning an x-ray mask to a pattern on a semiconductor slice utilizing an infrared light source and an alignment pattern pair on the mask and slice to automatically and precisely position the x-ray mask on the semiconductor slice.
Inventors
- 👤 Roderick K. Watts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:05
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; H; H10; H10W; H10W46/00; H10W46/501
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
The method of aligning a mask on a semiconductor slice comprising the steps of: forming a light transmissive pattern on a semiconductor slice, forming a matching opaque pattern on a mask, positioning said mask above said semiconductor slice with the matching patterns in approximate alignment, illuminating the bottom of said semiconductor slice with light signals, passing said light signals through said light transmissive pattern, and, placing said mask on said semiconductor slice and moving said mask to minimize the amount of said light signals that passes through said mask.
Claim 2
Independent Claim
89 words
The method of aligning a mask on a semiconductor slice comprising the steps of: forming a light transmissive pattern on a semiconductor slice, forming a matching opaque pattern on a mask, positioning said mask above said semiconductor slice with the matching patterns in approximate alignment, illuminating the bottom of said semiconductor slice with light signals, passing said light signals through said light transmissive pattern, and, placing said mask on said semiconductor slice and moving said mask to minimize the amount of said light signals that passes through said mask.
Claim 3
Dependent Claim
41 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: moving said mask in any direction in the x-y plane to minimize said light signals that have passed through said mask.
Claim 4
Dependent Claim
37 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: moving said mask to minimize said light signals that have passed through said mask in all directions.
Claim 5
Dependent Claim
42 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: positioning at least two detectors above said mask to detect the amount of said light signals that have passed through said mask.
Claim 6
Dependent Claim
36 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: effecting the relative motion between said mask and said semiconductor slice to maximize the alignment therebetween.
Claim 7
Dependent Claim
38 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: effecting the relative position of said mask to maximize the alignment between said mask and said semiconductor slice.
Claim 8
Dependent Claim
39 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: effecting the relative position of said semiconductor slice to maximize the alignment between said mask and said semiconductor slice.
Claim 9
Dependent Claim
36 words
The method of aligning a mask on a semiconductor slice as described in claim 1 further including the step of: effecting the relative position of said mask and said semiconductor slice to maximize the alignment therebetween.
Claim 10
Dependent Claim
44 words
The method of aligning a mask on a semiconductor slice as described in claim 4 further including the step of: applying the output from said detectors to a servo means, said servo means controlling the position of said mask relative to said semiconductor slice.
Claim 11
Dependent Claim
185 words
Apparatus for aligning a mask on a semiconductor slice comprising: an infrared laser source generating laser light capable of being transmitted through said semiconductor slice positioned to direct laser light through said semiconductor slice from the bottom surface thereof, a first mask means on the top surface of said semiconductor slice having orthogonal slits that are transparent to said laser light, a second mask means in proximate juxtaposed relationship to said first mask means and having orthogonal slits that are opaque to said laser light and when said first and second masks are in register eliminate the passage of laser light in the vicinity of said orthogonal slits, a first laser light detector positioned to receive laser light transmitted through one of said orthogonal slits of said second mask, a second laser light detector positioned to receive laser light transmitted through the other of said orthogonal slits of said second mask, and a servo circuit responsive to output signals from said first and second light detectors and effecting relative lateral translation of said first and second mask means to provide nulling of the detectors' outputs.
Claim 12
Dependent Claim
185 words
Apparatus for aligning a mask on a semiconductor slice comprising: an infrared laser source generating laser light capable of being transmitted through said semiconductor slice positioned to direct laser light through said semiconductor slice from the bottom surface thereof, a first mask means on the top surface of said semiconductor slice having orthogonal slits that are transparent to said laser light, a second mask means in proximate juxtaposed relationship to said first mask means and having orthogonal slits that are opaque to said laser light and when said first and second masks are in register eliminate the passage of laser light in the vicinity of said orthogonal slits, a first laser light detector positioned to receive laser light transmitted through one of said orthogonal slits of said second mask, a second laser light detector positioned to receive laser light transmitted through the other of said orthogonal slits of said second mask, and a servo circuit responsive to output signals from said first and second light detectors and effecting relative lateral translation of said first and second mask means to provide nulling of the detectors' outputs.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |