Patent US4831266A successfully refreshed from Google Patents.
US4831266A
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US
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Detector objective for particle beam apparatus
Assignee: ICT Integrated Circuit Testing Gesellschaft fuer Halbleiterprueftechnik mbH
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Filing: 1987-12-08
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Granted: 1989-05-16
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Expires: 2007-12-08
Abstract
Abstract A detector objective forms a component of an electron-optical column of a scanning electron microscope, the detector objective being composed of an asymmetrical magnetic lens, an electrostatic immersion lens generating a substantially rotationally symmetrical field, and an annular detector disposed immediately above the magnetic lens body. An electrode of the electrostatic immersion lens is formed as a truncated cone and is arranged in insulated fashion in an upper pole piece of the magnetic lens. The lower pole piece forms the second electrode of the immersion lens. The first and second electrodes are charged with potentials that establish an electrical field for decelerating the primary electrons, the electrical field overlying the focusing magnetic field.
Inventors
- 👤 Juergen Frosien
- 👤 Hans-Peter Feuerbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:51
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/10; H01J37/244; H01J2237/00; H01J2237/244; H01J2237/2441; H01J2237/2443; H01J2237/24435; H01J2237/2446; H01J2237/24465; H01J2237/2448; H01J2237/2449; H01J2237/245; H01J2237/24507
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
118 words
A detector objective for a particle beam apparatus, comprising: a magnetic lens for focusing a particle beam to a specimen; a detector arranged above a pole piece gap of said magnetic lens for detecting secondary particles triggered on the specimen; an electrostatic immersion lens overlying said magnetic lens said immersion lens having an upper electrode and a lower electrode; means for establishing a first potential at said upper electrode; means for establishing a second potential at said lower electrode to form an electrical field in said immersion lens, said first and second potentials being selected so that particles in said electrical field of said immersion lens are slowed down from a first energy to a second lower energy.
Claim 2
Dependent Claim
118 words
A detector objective for a particle beam apparatus, comprising: a magnetic lens for focusing a particle beam to a specimen; a detector arranged above a pole piece gap of said magnetic lens for detecting secondary particles triggered on the specimen; an electrostatic immersion lens overlying said magnetic lens said immersion lens having an upper electrode and a lower electrode; means for establishing a first potential at said upper electrode; means for establishing a second potential at said lower electrode to form an electrical field in said immersion lens, said first and second potentials being selected so that particles in said electrical field of said immersion lens are slowed down from a first energy to a second lower energy.
Claim 3
Dependent Claim
31 words
A detector objective as claimed in claim 1; wherein said first electrode of said electrostatic immersion lens is formed as a truncated cone of a hollow cylindrical projection at one end.
Claim 4
Dependent Claim
48 words
A detector objective as claimed in claim 1, wherein said magnetic lens has an axis of symmetry, said magnetic lens generating a substantially rotationally symmetrical magnetic field; said electrostatic immersion lens generating a substantially rotationally symmetrical electrical field, said electrostatic immersion lens being disposed within said magnetic lens.
Claim 5
Dependent Claim
36 words
A detector objective as claimed in claim 1, wherein said magnetic lens has an upper pole piece, and said first electrode of said electrostatic immersion lens is disposed in a bore in said upper pole piece.
Claim 6
Dependent Claim
31 words
A detector objective as claimed in claim 1, wherein said magnetic lens includes a lower pole piece and said lower pole piece forms said second electrode of said electrostatic immersion lens.
Claim 7
Dependent Claim
34 words
A detector objective as claimed in claim 1, wherein said magnetic lens includes an upper pole piece having a bore, said bore tapering in a shape of a truncated cone directed toward the specimen.
Claim 8
Dependent Claim
21 words
A detector objective as claimed in claim 1, wherein said magnetic lens includes an upper pole piece having a cylindrical bore.
Claim 9
Dependent Claim
25 words
A detector objective as claimed in claim 1, wherein said first electrode of said electrostatic immersion lens is in the form of a hollow cylinder.
Claim 10
Dependent Claim
20 words
A detector objective as claimed in claim 1, wherein said detector is disposed within a body of said magnetic lens.
Claim 11
Dependent Claim
21 words
A detector objective as claimed in claim 1, wherein said detector is disposed immediately above a body of said magnetic lens.
Claim 12
Dependent Claim
33 words
A detector objective as claimed in claim 1, wherein said detector is an annular detector that includes a hollow cylindrical shield disposed concentrically relative to said axis of symmetry of said magnetic lens.
Claim 13
Dependent Claim
37 words
A detector objective as claimed in claim 11, further comprising: means for maintaining said hollow cylindrical shield at a potential which is no more than a potential present at said first electrode of said electrostatic immersion lens.
Claim 14
Dependent Claim
17 words
A detector objective as claimed in claim 1, wherein said detector is a scintillator light guide combination.
Claim 15
Dependent Claim
15 words
A detector objective as claimed in claim 1, wherein said detector is a semiconductor detector.
Claim 16
Dependent Claim
17 words
A detector objective as claimed in claim 1, wherein said detector is a surface barrier layer detector.
Claim 17
Dependent Claim
22 words
A detector objective as claimed in claim 1, wherein said detector includes a particle sensitive region formed as a plurality of segments
Claim 18
Dependent Claim
14 words
A detector objective as claimed in claim 1, wherein said magnetic lens is symmetrical.
Claim 19
Dependent Claim
14 words
A detector objective as claimed in claim 1, wherein said magnetic lens is asymmetrical.
Claim 20
Dependent Claim
14 words
A detector objective as claimed in claim 1, wherein said magnetic lens is conical.
Claim 21
Dependent Claim
43 words
A detector objective as claimed in claim 1, wherein said first electrode of said electrostatic immersion lens is connected to means for providing at a positive potential, and said magnetic lens includes a lower pole piece connected to means for maintaining ground potential.
Claim 22
Dependent Claim
34 words
A detector objective as claimed in claim 1, further comprising: means for establishing a potential at said first electrode which is greater than a potential at said second electrode of said electrostatic immersion lens.
Claim 23
Dependent Claim
130 words
A detector objective for a particle beam apparatus, comprising: a magnetic lens defining a pole piece gap and having an axis of symmetry, said magnetic lens generating a substantially rotationally symmetrical magnetic field; an electrostatic immersion lens for generating a substantially rotationally symmetrical electrical field and including first and second electrodes lying at mutually different potentials, said electrostatic immersion lens being disposed within said magnetic lens symmetrically relative to said axis of symmetry; and a detector disposed above said pole piece gap of said magnetic lens symmetrically relative to said axis of symmetry, said detector documenting secondary particles triggered by a primary particle beam directed toward a specimen, said first electrode of said electrostatic immersion lens being formed as a truncated cone having a hollow cylindrical projection at one end.
Claim 24
Dependent Claim
130 words
A detector objective for a particle beam apparatus, comprising: a magnetic lens defining a pole piece gap and having an axis of symmetry, said magnetic lens generating a substantially rotationally symmetrical magnetic field; an electrostatic immersion lens for generating a substantially rotationally symmetrical electrical field and including first and second electrodes lying at mutually different potentials, said electrostatic immersion lens being disposed within said magnetic lens symmetrically relative to said axis of symmetry; and a detector disposed above said pole piece gap of said magnetic lens symmetrically relative to said axis of symmetry, said detector documenting secondary particles triggered by a primary particle beam directed toward a specimen, said first electrode of said electrostatic immersion lens being formed as a truncated cone having a hollow cylindrical projection at one end.
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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) | 1992-05-15 | 1992-11-14 | 1993-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-15 | 1996-11-14 | 1997-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-15 | 2000-11-14 | 2001-05-16 | $7700.00 | Window Closed / Lapsed |