Patent US5043586A successfully refreshed from Google Patents.
US5043586A
Expired / Lapsed
US
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Planarized, reusable calibration grids
Assignee: International Business Machines Corp
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Filing: 1990-10-25
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Granted: 1991-08-27
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Expires: 2010-10-25
Abstract
Abstract An improved structure for electron beam lithography grids and a method of fabricating such grids yields calibration grids having grid lines coplanar with the surface of a the grid body and laterally supported by grooves formed in the grid body and which can also be cleaned after contamination by outgassing resist during use by virtue of the provision of such lateral support for the grid lines. The grid exhibits improved accuracy due to the technique of fabrication of the grooves. The invention thus allows the electron beam lithography process to be conducted with less expense and at a greater speed. The improved accuracy of the calibration grid also permits integrated circuits and masks used in the fabrication of such devices to be designed more flexibly and fabricated at reduced cost and improved integration densities and manufacturing yields.
Inventors
- 👤 George J. Giuffre
- 👤 Maris A. Sturans
- 👤 James F. White
- 👤 Robert R. Wilbarg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:58
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
48 words
A calibration grid comprising a body having at least one groove in an exterior surface thereof and a material located in said at least one groove of said exterior surface of said body, said material having an electron backscattering characteristic which substantially differ from that of said body.
Claim 2
Dependent Claim
48 words
A calibration grid comprising a body having at least one groove in an exterior surface thereof and a material located in said at least one groove of said exterior surface of said body, said material having an electron backscattering characteristic which substantially differ from that of said body.
Claim 3
Dependent Claim
19 words
A calibration grid as recited in claim 1, wherein said material includes at least one of gold and tungsten.
Claim 4
Dependent Claim
29 words
A calibration grid as recited in claim 1 wherein a boundary between said groove and said material is smooth and highly linear in a direction parallel to said groove.
Claim 5
Dependent Claim
29 words
A calibration grid as recited in claim 1, wherein said surface of said body and a surface of said material which is not adjacent to said body are coplanar.
Claim 6
Dependent Claim
29 words
A calibration grid as recited in claim 3, wherein said surface of said body and a surface of said material which is not adjacent to said body are coplanar.
Claim 7
Dependent Claim
52 words
A grid comprising a body and grid lines of a material having an electron backscattering characteristic substantially differing from that of said body, said grid lines being located at a surface of said body wherein said body includes means for laterally supporting said grid lines in a direction parallel to said surface.
Claim 8
Dependent Claim
52 words
A grid comprising a body and grid lines of a material having an electron backscattering characteristic substantially differing from that of said body, said grid lines being located at a surface of said body wherein said body includes means for laterally supporting said grid lines in a direction parallel to said surface.
Claim 9
Dependent Claim
18 words
A grid as recited in claim 6, wherein said material includes at least one of gold and tungsten.
Claim 10
Dependent Claim
29 words
A grid as recited in claim 7, wherein said means for laterally supporting said grid lines comprises at least one groove formed in an exterior surface of said body.
Claim 11
Independent Claim
21 words
A method of operating an electron beam lithography machine having a calibration grid including the step of cleaning said calibration grid.
Claim 12
Independent Claim
21 words
A method of operating an electron beam lithography machine having a calibration grid including the step of cleaning said calibration grid.
Claim 13
Independent Claim
24 words
A method of cleaning a calibration grid for an electron beam lithography machine including a step of polishing a surface of said calibration grid.
Claim 14
Independent Claim
24 words
A method of cleaning a calibration grid for an electron beam lithography machine including a step of polishing a surface of said calibration grid.
Claim 15
Dependent Claim
24 words
A method of cleaning a calibration grid as recited in claim 10, wherein said polishing step includes polishing said surface with a diamond powder.
Claim 16
Independent Claim
24 words
A method of making a calibration grid for an electron beam lithography machine including a step of polishing a surface of said calibration grid.
Claim 17
Independent Claim
24 words
A method of making a calibration grid for an electron beam lithography machine including a step of polishing a surface of said calibration grid.
Claim 18
Dependent Claim
24 words
A method of ,making a calibration grid as recited in claim 12, wherein said polishing step includes polishing said surface with a diamond powder.
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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) | 1994-08-26 | 1995-02-25 | 1995-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-26 | 1999-02-25 | 1999-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-26 | 2003-02-25 | 2003-08-27 | $7700.00 | Window Closed / Lapsed |