Patent US4514638A successfully refreshed from Google Patents.
US4514638A
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Electron-optical system with variable-shaped beam for generating and measuring microstructures
Assignee: Advantest Corp
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Filing: 1984-08-22
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Granted: 1985-04-30
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Expires: 2004-08-22
Abstract
Abstract An electron-optical system with a variable-shaped beam for generating and measuring microstructures, such as circuits on a semiconductor substrate, generates the variable-shaped electron beam by the use of electron-optical shadow projection imaging and has a remote focus multipole Wehnelt electrode for adjusting, focusing, and controlling the intensity of the electron beam. The system also has a ferrite polecylinder in the beam projections lens with field attenuation or may have a beam projection lens with an external air gap. The length of the electron beam is approximately 60 centimeters.
Inventors
- 👤 Burkhard Lischke
- 👤 Juergen Frosien
- 👤 Klaus Anger
- 👤 Erich Plies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:59
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/06; H01J37/063; H01J37/09; H01J37/10; H01J37/14; H01J37/141; H01J37/30; H01J37/3002; H01J37/3007
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
148 words
An electron-optical system with a variable-shaped beam for generating and measuring microstructures at a beam target comprising in succession in the direction of beam travel: an electron source for generating an electron beam; a first lens means for focusing said electron beam which is a remote focus multipole Wehnelt electrode disposed adjacent to said electron source; at least one slot diaphragm for shaping the cross-section of said electron beam; a second lens means for generating an image of the shaped beam cross-section onto an intermediate image plane; and a third lens means for projecting said intermediate image of said shaped beam cross-section onto said target said first, second and third lens means and said slot diaphragm operating in combination as a shadow projection imaging means for generating said variable-shaped beam and said electron-optical system having no more that three lenses between said electron source and said target location.
Claim 2
Dependent Claim
148 words
An electron-optical system with a variable-shaped beam for generating and measuring microstructures at a beam target comprising in succession in the direction of beam travel: an electron source for generating an electron beam; a first lens means for focusing said electron beam which is a remote focus multipole Wehnelt electrode disposed adjacent to said electron source; at least one slot diaphragm for shaping the cross-section of said electron beam; a second lens means for generating an image of the shaped beam cross-section onto an intermediate image plane; and a third lens means for projecting said intermediate image of said shaped beam cross-section onto said target said first, second and third lens means and said slot diaphragm operating in combination as a shadow projection imaging means for generating said variable-shaped beam and said electron-optical system having no more that three lenses between said electron source and said target location.
Claim 3
Dependent Claim
35 words
The electron-optical system of claim 1 wherein said third lens means is a projection lens disposed immediately above said target location in the direction of beam travel and having a ferrite polecylinder with field attenuation.
Claim 4
Dependent Claim
53 words
The electron-optical system of claim 2 wherein said projection lens further comprises a dynamic focusing coil and a plurality of beam deflecting elements and wherein said polecylinder has a bore through which said beam travels having smaller radial dimensions than the radial dimensions of said dynamic focusing coil and said beam deflecting elements.
Claim 5
Dependent Claim
32 words
The electron-optical system of claim 1 wherein said third lens means is a projection lens disposed immediately above said target location in a direction of beam travel having an external air gap.
Claim 6
Dependent Claim
31 words
The electron-optical system of claim 1 further comprising a magnetic condenser lens and a magnetic projection lens successively disposed between said means for generating said variable-shaped beam and said target location.
Claim 7
Dependent Claim
30 words
The electron-optical system of claim 1 wherein said electron beam has a beam path defined by the distance between said electron source and said target location of approximately 60 centimeters.
Claim 8
Dependent Claim
105 words
The electron-optical system of claim 1 further comprising: a second slot diaphragm; a first beam deflection system; and a third slot diaphragm, said second slot diaphragm, said first beam deflection system and said third slot diaphragm being successively disposed in the direction of travel of said beam after said first slot diaphragm and before said second lens means, said first deflection system deflecting said electron beam with respect to an optical axis of said electron-optical system after passage of said beam through second slot diaphragm such that only a portion of the beam emerging from said second slot diaphragm passes through said third slot diaphragm.
Claim 9
Dependent Claim
40 words
The electron-optical system of claim 8 further comprising: a second beam deflection system and a third beam deflection system successively disposed in a direction of beam travel after said third slot diaphragm for returning said beam to said optical axis.
Claim 10
Dependent Claim
18 words
The electron-optical system of claim 8 wherein said second and third slot diaphragm are comprised of enameled carbon.
Claim 11
Dependent Claim
26 words
The electron-optical system of claim 8 wherein said second and third slot diaphragms consist of a metal having a high melting point with a graphite coating.
Claim 12
Dependent Claim
14 words
The electron-optical system of claim 1 wherein said slot diaphragm consists of enameled carbon.
Claim 13
Dependent Claim
23 words
The electron-optical system of claim 1 wherein said slot diaphragm consists of a metal having a high melting point with a graphite coating.
Claim 14
Dependent Claim
20 words
The electron-optical system of claim 9 wherein said focusing means includes a means for rotating said line of said beam.
Claim 15
Dependent Claim
23 words
The electron-optical system of claim 16 wherein said means for rotating said beam line is a Wehnelt electrode with auxiliary voltages supplied thereto.
Claim 16
Dependent Claim
40 words
The electron-optical system of claim 1 wherein said intermediate image plane is disposed at a second of said beam crossover points in a direction of beam travel and further comprising a beam blanking system disposed at said intermediate image plane.
Claim 17
Dependent Claim
36 words
The electron-optical system of claim 1 wherein said third lens means is a projection lens disposed immediately above said target location in a direction of beam travel having a fine focus coil with compensated image rotation.
Claim 18
Dependent Claim
29 words
The electron-optical system of claim 1 further comprising an anode and wherein a first of said beam crossovers in a direction of beam travel is disposed behind said anode.
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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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |