Patent US3597607A successfully refreshed from Google Patents.
US3597607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron probe employing three secondary emission detectors whose outputs are combined to minimize error
Assignee: Leica Microsystems Inc
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Filing: 1968-02-16
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Granted: 1971-08-03
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Expires: 1988-02-16
Abstract
Abstract In electron beam apparatus in which an electron beam is caused to impinge on a specimen surface and the backscattered electrons are detected and used to produce an image-giving information about the surface, instead of using a single detector, which cannot distinguish between changes in signal due to material and changes due to topography, and instead of using two detectors which can eliminate changes due to material but only show topographical features in certain directions, it is proposed to use at least three detectors, symmetrically arranged, and to combine their signals in such a way as to allow observation of topography without regard to angular position or with regard to a direction of apparent illumination that is variable at will.
Inventors
- 👤 Alistair John Campbell
- 👤 Andrew D G Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:35
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/20; G01N23/203
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
148 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent on the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output where do, d1 ... dn 1 are the electric signals from said detectors, and theta is the angle between an arbitrary direction lying in a plane normal to the beam and the projection, onto said plane, of a line joining the path of the beam to that detector which produces the output do.
Claim 2
Dependent Claim
148 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent on the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output where do, d1 ... dn 1 are the electric signals from said detectors, and theta is the angle between an arbitrary direction lying in a plane normal to the beam and the projection, onto said plane, of a line joining the path of the beam to that detector which produces the output do.
Claim 3
Dependent Claim
121 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent on the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output D1 d1-do + d1-d1 + d1-d2 +... where do, d1 ... dn 1 are the electrical signals from said detectors and d1 1/n(do+d1+ ... dn 1).
Claim 4
Dependent Claim
121 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent on the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output D1 d1-do + d1-d1 + d1-d2 +... where do, d1 ... dn 1 are the electrical signals from said detectors and d1 1/n(do+d1+ ... dn 1).
Claim 5
Dependent Claim
117 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent of the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output D11 (d1-do)2+(d1-d1)2+ ... where do, d1 ... dn 1 are the electric signals from said detectors and d1 1/n(do+d1+ ... dn 1).
Claim 6
Dependent Claim
117 words
Electron beam apparatus comprising means for causing an electron beam to impinge on the surface of a specimen placed in the path of said beam, an array of n electron detectors, n being at least three, spaced symmetrically around the path of said beam in positions to pick up resultant backscattered electrons from said specimen surface, said detectors producing electrical signals dependent of the backscattered electrons picked up, means for causing relative lateral scanning between said beam and said specimen surface, and an electric mixing circuit, said mixing circuit being arranged to produce an output D11 (d1-do)2+(d1-d1)2+ ... where do, d1 ... dn 1 are the electric signals from said detectors and d1 1/n(do+d1+ ... dn 1).
Claim 7
Dependent Claim
21 words
The apparatus of claim 1 including means associated with said mixing circuit for varying the value of the angle theta .
Claim 8
Dependent Claim
31 words
The apparatus of claim 1 including switching means associated with said mixing circuit to allow selection at will of a signal representing the sum of the outputs of all said detectors.
Claim 9
Dependent Claim
36 words
The apparatus of claim 1 further including switching means associated with said mixing circuit and allowing at will the selection of a signal D1 d1-do + d1-d1 +d1-d2 + ... where d1 1/n(do+d1+ ... +dn 1).
Claim 10
Dependent Claim
32 words
The apparatus of claim 1 further including switching means associated with said mixing circuit and allowing the selection at will of a signal: D11 (d1-do)2+(d1-d1)2+ ... where d1 1/n(do+d1+ ... +dn 1).
Claim 11
Dependent Claim
26 words
The apparatus of claim 2 further including switching means associated with said mixing circuit and allowing the selection at will of a signal: D11 (d1-do)2+(d1-d1)2+ ...
Claim 12
Independent Claim
132 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deriving from said signals an output signal where do, d1...dn 1 are the electric signals from said detectors, and is the angle between an arbitrary direction lying in a plane normal to the beam and the projection, onto said plane, of a line joining the path of the beam to that detector which produces the output do.
Claim 13
Independent Claim
132 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deriving from said signals an output signal where do, d1...dn 1 are the electric signals from said detectors, and is the angle between an arbitrary direction lying in a plane normal to the beam and the projection, onto said plane, of a line joining the path of the beam to that detector which produces the output do.
Claim 14
Independent Claim
103 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deriving from said signals an output signal D1 d1-do + d1-d1 +d1-d2 +... where do, d1...dn 1 are the electrical signals from said detectors and d1 1/n(do+d1+...dn 1).
Claim 15
Independent Claim
103 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deriving from said signals an output signal D1 d1-do + d1-d1 +d1-d2 +... where do, d1...dn 1 are the electrical signals from said detectors and d1 1/n(do+d1+...dn 1).
Claim 16
Independent Claim
99 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deRiving from said signals an output signal D11 (d1-do)2+(d1-d1)2+... where do, d1...dn 1 are the electric signals from said detectors and d1 1/n(do+d1+...dn 1).
Claim 17
Independent Claim
99 words
A method of determining the topography of the surface of a specimen comprising causing an electron beam to impinge on said surface, detecting the resultant electrons back scattered from said surface by means of an array of n separate detectors, n being at least three, symmetrically spaced around the path of said beam, causing relative lateral scanning between said beam and said specimen surface, deriving from the detectors at least three corresponding electrical signals and deRiving from said signals an output signal D11 (d1-do)2+(d1-d1)2+... where do, d1...dn 1 are the electric signals from said detectors and d1 1/n(do+d1+...dn 1).
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |