US3874916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mask alignment system for electron beam pattern generator
Assignee: Radiant Energy Systems Inc
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Filing: 1972-06-23
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Granted: 1975-04-01
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Expires: 1992-06-23
Abstract
Abstract A mask alignment system for electron beam pattern generators whereby an electron beam pattern may be repeatedly directed to a mask blank in an extremely accurate predetermined matrix pattern. In accordance with the invention a master mask is fabricated having a reference grid pattern thereon. This reference pattern is reproduced as an electrically conductive grid pattern on each electron sensitized mask blank for a mask set. Electrical connection is made to the grid pattern, when the mask blank is placed in an electron beam pattern generator, and controlled scanning of the beam is used to intercept the reference grid and provide an output signal current as the result thereof so as to allow correction of the electron beam pattern position for the error in position in the mask blank because of step and repeat inaccuracies in the X-Y positioner supporting the mask blank. Perfection in the master grid is not required since deviations from the true desired position will repeat throughout the mask set, so as to allow proper alignment of each mask in the mask set throughout the entire mask plane.
Inventors
- 👤 William R Livesay
- 👤 Malcolm E Wing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:37
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045; G; G03; G03F; G03F1/00; G03F1/38; G03F1/42; G03F1/68; G03F1/76; G03F1/78; H10; H10P; H10P95/00; Y; Y10; Y10S; Y10S430/00; Y10S430/143; Y10T; Y10T428/00; Y10T428/25
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
57 words
A MASK BLANK FROM WHICH A PHOTOMASK MAY BE PRODUCED FOR USE IN INTEGRATED CIRCUIT FABRICATION PROCESSES, SAID MASK BLANK COMPRISING: A TRANSPARENT, ELECTRICALLY NONCONDUCTIVE SUBSTRATE FOR SUPPORTING A PHOTOMASK; A FIRST LAYER OF ELECTRICALLY CONDUCTIVE METAL MASKING MATERIAL ON ONE SURFACE OF SAID SUBSTRATE; A SECOND LAYER OF ELECTRON SENSITIZED MATERIAL OVER SAID FIRST LAYER; AND
Claim 2
Dependent Claim
57 words
A MASK BLANK FROM WHICH A PHOTOMASK MAY BE PRODUCED FOR USE IN INTEGRATED CIRCUIT FABRICATION PROCESSES, SAID MASK BLANK COMPRISING: A TRANSPARENT, ELECTRICALLY NONCONDUCTIVE SUBSTRATE FOR SUPPORTING A PHOTOMASK; A FIRST LAYER OF ELECTRICALLY CONDUCTIVE METAL MASKING MATERIAL ON ONE SURFACE OF SAID SUBSTRATE; A SECOND LAYER OF ELECTRON SENSITIZED MATERIAL OVER SAID FIRST LAYER; AND
Claim 3
Dependent Claim
11 words
The mask blank of claim 1 wherein said substrate is glass.
Claim 4
Dependent Claim
14 words
The maSk blank of claim 2 wherein said electrically conductive masking material is chromium.
Claim 5
Dependent Claim
93 words
A mask blank from which a photomask may be produced for use in integrated circuit fabrication processes, said mask blank comprising: a transparent, electrically nonconductive substrate for supporting a photomask; a first layer of electrically nonconductive masking material on one surface of said substrate; a second layer of electrically conductive metal material over said first layer, said second layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns; and a third layer of electron sensitized material over said second layer.
Claim 6
Dependent Claim
93 words
A mask blank from which a photomask may be produced for use in integrated circuit fabrication processes, said mask blank comprising: a transparent, electrically nonconductive substrate for supporting a photomask; a first layer of electrically nonconductive masking material on one surface of said substrate; a second layer of electrically conductive metal material over said first layer, said second layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns; and a third layer of electron sensitized material over said second layer.
Claim 7
Dependent Claim
31 words
The mask blank of claim 4 further comprised of a fourth layer of electrically conductive metal material over said third layer, said fourth layer being electrically insulated from said second layer.
Claim 8
Dependent Claim
11 words
The mask blank of claim 5 wherein said substrate is glass.
Claim 9
Dependent Claim
12 words
The mask blank of claim 6 wherein said first layer is silicon.
Claim 10
Dependent Claim
115 words
A combination for detecting the position of a mask blank in an electron beam pattern generator, comprising: a mask blank having a transparent electrically nonconductive substrate for supporting a photomask, a first layer of electrically conductive metal masking material on one surface of said substrate, a second layer of electron sensitized material over said first layer, and a third layer of electrically conductive metal material over said second layer, said third layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns; and means for making electrical contact with said third layer to sense the presence of an electron beam current impinging thereon.
Claim 11
Dependent Claim
115 words
A combination for detecting the position of a mask blank in an electron beam pattern generator, comprising: a mask blank having a transparent electrically nonconductive substrate for supporting a photomask, a first layer of electrically conductive metal masking material on one surface of said substrate, a second layer of electron sensitized material over said first layer, and a third layer of electrically conductive metal material over said second layer, said third layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns; and means for making electrical contact with said third layer to sense the presence of an electron beam current impinging thereon.
Claim 12
Dependent Claim
21 words
A combination as set forth in claimm 8, further comprising means for electrically coupling said first layer to a predetermined voltage.
Claim 13
Dependent Claim
135 words
A combination for detecting the position of a mask blank in an electron beam pattern generator, comprising: a mask blank having a transparent, electrically nonconductive substrate for supporting a photomask, a first layer of electrically nonconductive masking material on one surface of said substrate, a second layer of electrically conductive metal material over said first layer, said second layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns, a third layer of electron sensitized material over said second layer, and a fourth layer of electrically conductive material over said third layer, said fourth layer being electrically insulated from said second layer; and means for making electrical contact with said second layer to sense the presence of an electron beam current impinging thereon.
Claim 14
Dependent Claim
135 words
A combination for detecting the position of a mask blank in an electron beam pattern generator, comprising: a mask blank having a transparent, electrically nonconductive substrate for supporting a photomask, a first layer of electrically nonconductive masking material on one surface of said substrate, a second layer of electrically conductive metal material over said first layer, said second layer being patterned to form a repetitive, electrically interconnected pattern in the interstices between areas for formation of a matrix of circuit patterns, a third layer of electron sensitized material over said second layer, and a fourth layer of electrically conductive material over said third layer, said fourth layer being electrically insulated from said second layer; and means for making electrical contact with said second layer to sense the presence of an electron beam current impinging thereon.
Claim 15
Dependent Claim
21 words
A combination as set forth in claim 10, further comprising means for electrically coupling said first layer to a predetermined voltage.
Claim 16
Dependent Claim
91 words
A mask blank from which a photomask may be produced for use in integrated circuit fabrication processes, said mask blank comprising: a transparent, electrically nonconductive substrate for supporting a photomask; a layer of masking material over a first surface of said substrate; and a patterned layer of electrically conductive metal material over said first surface and disposed to form a repetitive, electrically interconnected pattern defining areas of a matrix of circuit patterns to be formed, said patterned layer being electrically insulated from all other electrically conductive materials on said mask blank.
Claim 17
Dependent Claim
91 words
A mask blank from which a photomask may be produced for use in integrated circuit fabrication processes, said mask blank comprising: a transparent, electrically nonconductive substrate for supporting a photomask; a layer of masking material over a first surface of said substrate; and a patterned layer of electrically conductive metal material over said first surface and disposed to form a repetitive, electrically interconnected pattern defining areas of a matrix of circuit patterns to be formed, said patterned layer being electrically insulated from all other electrically conductive materials on said mask blank.
Claim 18
Dependent Claim
26 words
The mask blank of claim 12, further including at least one additional, substantially continuous layer of electrically conductive metal material electrically insulated from said patterned layer.
Claim 19
Dependent Claim
148 words
A combination for detecting the position of a mask blank in an electron beam Pattern generator, comprising: a mask blank having a transparent, electrically nonconductive substrate for supporting a photomask, a layer of masking material over a first surface of said substrate, a patterned layer of electrically conductive metal material over said first surface and disposed to form a repetitive, electrically interconnected pattern defining areas of a matrix of circuit patterns to be formed, said patterned layer being electrically insulated from all other electrically conductive materials on said mask blank, and at least one additional, substantially continuous layer of electrically conductive metal material electrically insulated from said patterned layer; means for establishing electrical contact with said patterned layer to detect the presence of an electron beam current impinging thereon; and means for establishing electrical contact with said additional, substantially continuous layer to determine the voltage on said layer.
Claim 20
Dependent Claim
148 words
A combination for detecting the position of a mask blank in an electron beam Pattern generator, comprising: a mask blank having a transparent, electrically nonconductive substrate for supporting a photomask, a layer of masking material over a first surface of said substrate, a patterned layer of electrically conductive metal material over said first surface and disposed to form a repetitive, electrically interconnected pattern defining areas of a matrix of circuit patterns to be formed, said patterned layer being electrically insulated from all other electrically conductive materials on said mask blank, and at least one additional, substantially continuous layer of electrically conductive metal material electrically insulated from said patterned layer; means for establishing electrical contact with said patterned layer to detect the presence of an electron beam current impinging thereon; and means for establishing electrical contact with said additional, substantially continuous layer to determine the voltage on said layer.
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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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |