US3876879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining surface characteristics incorporating a scanning electron microscope
Assignee: Calspan Corp
•
Filing: 1973-11-09
•
Granted: 1975-04-08
•
Expires: 1993-11-09
Abstract
Abstract Method and apparatus for determining surface characteristics such as elevations of points on a surface wherein; an electron beam scans the surface causing electrons to be emitted from the surface; an electron sensitive detector develops signals in response to the emitted electrons impinging thereupon; a shield is located above the surface for blocking electrons emitted from an area of the surface from reaching the detector, the boundary of the area comprising a line that is a function of the elevation or contour of points on the surface, which line is sensed by the detector as a locus of points on the surface wherein the output of the detector abruptly changes in value.
Inventors
- 👤 Hiramie T Mcadams
- 👤 Edward A Gasiecki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:44
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/22; G01N23/225; G01B; G01B15/00; G01B15/04; G01B15/08; H; H01; H01J; H01J37/00; H01J37/26; H01J37/28
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
108 words
A method of enabling the determination of surface elevation, comprising the steps of: a. projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detecting by means of a detector electrons emitted from the surface, c. blocking from being detected by blocking means electrons emitted from a first area of the surface, the relative positions of the detector and the blocking means being predetermined, and d. locating the boundary of said first area by detecting the location of points on the surface at which the output of the detector abruptly changes in value whereby the relative elevations of said points can be determined.
Claim 2
Independent Claim
108 words
A method of enabling the determination of surface elevation, comprising the steps of: a. projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detecting by means of a detector electrons emitted from the surface, c. blocking from being detected by blocking means electrons emitted from a first area of the surface, the relative positions of the detector and the blocking means being predetermined, and d. locating the boundary of said first area by detecting the location of points on the surface at which the output of the detector abruptly changes in value whereby the relative elevations of said points can be determined.
Claim 3
Dependent Claim
54 words
The method according to claim 1, further comprising the steps of: e. blocking from being detected electrons emitted from a second area of the surface, and f. locating the boundary of the second area by detecting the location of points on the surface at which the output of the detector abruptly changes in value.
Claim 4
Dependent Claim
62 words
The method according to claim 2, further comprising the steps of: g. blocking from being detected electrons emitted from a plurality of additional areas on the surface, and h. repetitively locating the boundaries of said additional areas by repetitively detecting the location of points on the surface for each additional area at which the output of the detector abruptly changes in value.
Claim 5
Dependent Claim
19 words
The method according to claim 3 wherein said step of blocking additional areas is accomplished by moving the surface.
Claim 6
Dependent Claim
17 words
The method according to claim 3 wherein said beam of electrons is caused to scan the surface.
Claim 7
Dependent Claim
18 words
The method according to claim 5 further comprising the step of: i. recording the output of the detector.
Claim 8
Dependent Claim
33 words
The method according to claim 5 further comprising the steps of: i. displaying the output of the detector on a display device, and j. synchronizing the display device with the scanning electron beam.
Claim 9
Dependent Claim
118 words
Apparatus for enabling the determination of surface elevation with respect to a datum plane, comprising: a. means for projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detection means for detecting electrons emitted from the surface, c. means for blocking electrons emitted from a first area of the surface from being detected by said detection means, the relative positions of said detection means and said means for blocking being predetermined, and d. means for locating the boundary of said first area by detecting the location of points on the surface at which the output of said detection means abruptly changes in value whereby the relative elevations of said points can be determined.
Claim 10
Dependent Claim
118 words
Apparatus for enabling the determination of surface elevation with respect to a datum plane, comprising: a. means for projecting a beam of electrons on a surface causing electrons to be emitted therefrom, b. detection means for detecting electrons emitted from the surface, c. means for blocking electrons emitted from a first area of the surface from being detected by said detection means, the relative positions of said detection means and said means for blocking being predetermined, and d. means for locating the boundary of said first area by detecting the location of points on the surface at which the output of said detection means abruptly changes in value whereby the relative elevations of said points can be determined.
Claim 11
Dependent Claim
26 words
The apparatus according to claim 8, wherein said blocking means comprises a shield spaced from the surface and located between the surface and said detection means.
Claim 12
Dependent Claim
41 words
The apparatus according to claim 9, wherein said shield has an edge and the boundary of the first area is a line which is defined by the intersection of the surface by a plane containing said edge and said detection means.
Claim 13
Dependent Claim
19 words
The apparatus according to claim 10, wherein said plane makes a predetermined angle with respect to the datum plane.
Claim 14
Dependent Claim
26 words
The apparatus according to claim 11, further comprising: e. means for blocking electrons from additional areas of the surface from being detected by said detection means.
Claim 15
Dependent Claim
23 words
The apparatus according to claim 12, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
Claim 16
Dependent Claim
25 words
The apparatus according to claim 12, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
Claim 17
Dependent Claim
33 words
The apparatus according to claim 14, further comprising: f. a display device for displaying the output of said detection means, and g. means for synchronizing the display device with said scanning electron beam.
Claim 18
Dependent Claim
13 words
The apparatus according to claim 11 wherein said angle is substantially ninety degrees.
Claim 19
Dependent Claim
18 words
The apparatus according to claim 8, further comprising: e. means for recording the output of said detection means.
Claim 20
Dependent Claim
25 words
The apparatus according to claim 8, wherein said means for projecting a beam of electrons includes means for causing said beam to scan the surface.
Claim 21
Dependent Claim
18 words
The apparatus according to claim 18, further comprising: e. means for recording the output of said detection means.
Claim 22
Dependent Claim
33 words
The apparatus according to claim 18 further comprising: e. a display device for displaying the output of said detection means, and f. means for synchronizing the display device with said scanning electron beam.
Claim 23
Dependent Claim
24 words
The apparatus according to claim 8, wherein said blocking means is spaced from the surface and located between the surface and said detection means.
Claim 24
Dependent Claim
66 words
The apparatus according to claim 21, further comprising: e. an extremity of said blocking means, f. an electron sensitive portion of said detection means having an area approaching that of a point, and wherein the boundary of the first area is a line on the surface which is defined by the intersection of the surface by a plane containing said extremity and said electron sensitive portion.
Claim 25
Dependent Claim
26 words
The apparatus according to claim 22, further comprising: g. means for blocking electrons from additional areas of the surface from falling on said electron sensitive portion.
Claim 26
Dependent Claim
23 words
The apparatus according to claim 23, wherein said last mentioned means comprises means for moving the surface with respect to said blocking means.
Claim 27
Dependent Claim
14 words
The apparatus according to claim 8, wherein said detection means comprises a backscatter detector.
Claim 28
Dependent Claim
16 words
The apparatus according to claim 8, wherein said detector means comprises an unbiased secondary emission detector.
References Cited (Backward Citations)
US3597607A
Cited
US3549999A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |