US4812651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrometer objective for particle beam measuring instruments
Assignee: Advantest Corp
•
Filing: 1987-11-13
•
Granted: 1989-03-14
•
Expires: 2007-11-13
Abstract
Abstract A spectrometer objective includes a generally asymmetrical objective lens having a short focal length, a deflection system disposed within the objective lens symmetrically relative to an optical axis, and an electrostatic retarding field spectrometer including an electrode arrangement for accelerating the secondary electrons generated on the specimen. The electrode arrangement of the retarding field spectrometer includes an electrode pair for establishing a spherically symmetrical retarding field. The electrode arrangement for extracting and accelerating the secondary particles includes a grid electrode disposed in a region of the lower pole piece of the objective lens and of a planar electrode disposed in the particle beam path immediately above the specimen, wherein the planar electrode is charged with a potential lying between the potential of the specimen and the potential of the grid electrode.
Inventors
- 👤 Hans-Peter Feuerbaum
- 👤 Juergen Frosien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:14
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/10; H01J37/14; H01J37/05; H01J37/244; H01J37/26; H01J37/266; H01J37/268; H01J2237/00; H01J2237/05; H01J2237/057; H01J2237/244; H01J2237/2448; H01J2237/2449; H01J2237/245; H01J2237/24507; H01J2237/24571; H01J2237/24585
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
114 words
An improved spectrometer objective for use in a particle beam measuring instrument having a particle beam directed onto a specimen and an electrode arrangement for generating an retarding electrical field, the improvement comprising: an extraction grid electrode at a first predetermined potential for extracting and accelerating secondary particles generated at the specimen by the particle beam toward the retarding electrical field; and a planar electrode disposed between said extraction grid electrode and the speciment and having a second predetermined potential, said second predetermined potential being less than said first predetermined potential and not less than the potential of the specimen to provide a uniform electrical field between said planar electrode and said extraction electrode.
Claim 2
Dependent Claim
114 words
An improved spectrometer objective for use in a particle beam measuring instrument having a particle beam directed onto a specimen and an electrode arrangement for generating an retarding electrical field, the improvement comprising: an extraction grid electrode at a first predetermined potential for extracting and accelerating secondary particles generated at the specimen by the particle beam toward the retarding electrical field; and a planar electrode disposed between said extraction grid electrode and the speciment and having a second predetermined potential, said second predetermined potential being less than said first predetermined potential and not less than the potential of the specimen to provide a uniform electrical field between said planar electrode and said extraction electrode.
Claim 3
Dependent Claim
46 words
An improved spectrometer objective as claimed in claim 1, wherein said first predetermined potential is in the range of 1 through 5 kilovolts, said second predetermined potential is in the range of 0 through 100 volts, and said planar electrode is disposed immediately above the specimen.
Claim 4
Dependent Claim
172 words
A spectrometer lens, comprising: a magnetic lens operable to focus a primary particle beam onto a specimen and having a lower pole piece; a retarding field spectrometer having: a planar first electrode arranged immediately above the specimen and connectable to a first potential, said first electrode being immediately under or within said lens, a planar second electrode arranged above said first electrode in or at said lower pole piece of said magnetic lens, said second electrode being connectable to a second potential wherein said first and second potentials establish a uniform electrical field in a special region between said first and second electrodes for accelerating the secondary particles triggered at said specimen by the primary particle beam in a direction of said magnetic lens, and third and fourth electrodes arranged above said second electrode, said third electrode being connectable to said second potential and said fourth electrode being connectable to a potential which establishes an electrical field in a spacial region between said third and fourth electrodes for decelerating said secondary particles.
Claim 5
Dependent Claim
172 words
A spectrometer lens, comprising: a magnetic lens operable to focus a primary particle beam onto a specimen and having a lower pole piece; a retarding field spectrometer having: a planar first electrode arranged immediately above the specimen and connectable to a first potential, said first electrode being immediately under or within said lens, a planar second electrode arranged above said first electrode in or at said lower pole piece of said magnetic lens, said second electrode being connectable to a second potential wherein said first and second potentials establish a uniform electrical field in a special region between said first and second electrodes for accelerating the secondary particles triggered at said specimen by the primary particle beam in a direction of said magnetic lens, and third and fourth electrodes arranged above said second electrode, said third electrode being connectable to said second potential and said fourth electrode being connectable to a potential which establishes an electrical field in a spacial region between said third and fourth electrodes for decelerating said secondary particles.
Claim 6
Dependent Claim
21 words
A spectrometer lens as claimed in claim 3, wherein said first electrode and said specimen are both at said first potential.
Claim 7
Dependent Claim
25 words
A spectrometer lens as claimed in claim 3, wherein said first potential connectable to said first electrode is between approximately 0 and 100 volts, inclusive.
Claim 8
Dependent Claim
23 words
A spectrometer lens as claimed in claim 3, wherein said first electrode is held at said lower pole piece of said magnetic lens.
Claim 9
Dependent Claim
23 words
A spectrometer lens as claimed in claim 3, wherein said first electrode is held within said lower pole piece of said magnetic lens.
Claim 10
Dependent Claim
17 words
A spectrometer lens as claimed in claim 3, wherein said first electrode includes an annular mounting part.
Claim 11
Dependent Claim
16 words
A spectrometer lens as claimed in claim 3, wherein said first electrode is a grid electrode.
Claim 12
Dependent Claim
16 words
A spectrometer lens as claimed in claim 3, wherein said first electrode is a diaphram electrode.
Claim 13
Dependent Claim
20 words
A spectrometer lens as claimed in claim 3, wherein said third and fourth electrodes are arranged above said magnetic lens.
Claim 14
Dependent Claim
20 words
A spectrometer lens as claimed in claim 3, wherein said third and fourth electrodes are arranged inside said magnetic lens.
Claim 15
Dependent Claim
90 words
A spectrometer lens as claimed in claim 3, wherein said third electrode is shaped as a surface portion of a first sphere having a first radius, said fourth electrode being shaped as a surface portion of a second sphere having a second radius, said first and second spheres having centers coincident at a point lying on an optical axis of said magnetic lens so that said potentials connectable to said third and fourth electrodes establish a spherically symmetrical retarding field in a spacial region between said third and fourth electrodes.
Claim 16
Dependent Claim
26 words
A spectrometer lens as claimed in claim 13, wherein said coincident centers of said first and second spheres lie in a space free of electrical fields.
Claim 17
Dependent Claim
15 words
A spectrometer lens as claimed in claim 14 wherein said deflection system is Wien filter.
Claim 18
Dependent Claim
35 words
A spectrometer lens as claimed in claim 13, further comprising: a deflection system having a center point said center point of said deflection system being coincident with said centers of said first and second spheres.
Claim 19
Dependent Claim
16 words
A spectrometer lens as claimed in claim 16, wherein said deflection system is a Wien filter.
Claim 20
Dependent Claim
24 words
A spectrometer lens as claimed in claim 3, further comprising: a deflection system integrated into said magnetic lens and arranged above said second electrodes.
References Cited (Backward Citations)
US3896308A
Cited
US4514682A
Cited
US4587425A
Cited
US4658137A
Cited
US4683376A
Cited
US4694170A
Cited
US4675524A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |