US4475037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of inspecting a mask using an electron beam vector scan system
Assignee: International Business Machines Corp
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Filing: 1982-05-11
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Granted: 1984-10-02
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Expires: 2002-05-11
Abstract
Abstract An electron beam fabricated mask used in the production of integrated circuits is tested by a method that includes the steps of forming a print of the mask and then inspecting the print by writing the same electron beam pattern or complement thereof on the print and detecting pattern coincidence and non-coincidence with a vector scan system.
Inventors
- 👤 Peter Vettiger
- 👤 Alan D. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:11
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
61 words
A method of inspecting a mask formed by writing a pattern from pattern data comprising the steps of forming a print from the mask on a substrate, overlaying on said print a corresponding electron beam pattern or complement thereof from said pattern data, and detecting a point of coincidence or noncoincidence of the electron beam pattern with respect to said print.
Claim 2
Independent Claim
61 words
A method of inspecting a mask formed by writing a pattern from pattern data comprising the steps of forming a print from the mask on a substrate, overlaying on said print a corresponding electron beam pattern or complement thereof from said pattern data, and detecting a point of coincidence or noncoincidence of the electron beam pattern with respect to said print.
Claim 3
Dependent Claim
38 words
A method as described in claim 1 including the step of forming a plurality of prints on the substrate and comparing a point of coincidence or noncoincidence on one print with at least one of said other prints.
Claim 4
Dependent Claim
14 words
A method as described in claim 1 whereby said print is made of gold.
Claim 5
Dependent Claim
21 words
A method as described in claim 1 whereby a vector scan system is used to detect points of coincidence and noncoincidence.
Claim 6
Dependent Claim
17 words
A method as described in claim 1 whereby the electron beam pattern is registered with said print.
Claim 7
Dependent Claim
23 words
A method as described in claim 1 whereby a corresponding electron beam pattern complement from said pattern data is overlaid on said print.
Claim 8
Dependent Claim
17 words
A method as described in claim 1 including detecting a plurality of points of coincidence or noncoincidence.
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) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |