Claims
- 1. An electron beam column comprising:
a probe optics assembly, for forming an electron probe; an electron optical axis, defined by said probe optics assembly; a secondary electron detector situated below said probe optics assembly; and a detector optics assembly, asymmetrical with respect to said electron optical axis, situated below said probe optics assembly.
- 2. An electron beam column as in claim 1, wherein said detector optics assembly comprises a field free tube, asymmetrical with respect to said electron optical axis, situated between said probe optics assembly and said secondary electron detector.
- 3. An electron beam column as in claim 2, wherein said detector optics assembly further comprises a voltage contrast plate situated below said field free tube and said secondary electron detector.
- 4. An electron beam column as in claim 1, wherein said detector optics comprises a voltage contrast plate, asymmetrical with respect to said electron optical axis, situated below said secondary electron detector.
- 5. An electron beam column as in claim 4, wherein said detector optics assembly further comprises a field free tube situated between said probe optics assembly and said voltage contrast plate.
- 6. An electron beam column as in claim 2, wherein said detector optics assembly further comprises a voltage contrast plate, asymmetrical with respect to said electron optical axis.
- 7. An electron beam column as in claim 2, wherein said field free tube has a chamfered lower end.
- 8. An electron optical column as in claim 7, wherein said field free tube has a circular bore and a square perimeter.
- 9. An electron beam column as in claim 2, wherein said field free tube is offset from said electron optical axis.
- 10. An electron optical column as in claim 4, wherein said voltage contrast plate is offset from said electron optical axis.
- 11. An electron optical column as in claim 4, wherein said voltage contrast plate has a notch in the aperture.
- 12. An electron optical column as in claim 4, wherein said voltage contrast plate has a bump on the aperture.
- 13. An electron optical column as in claim 6, wherein said field free tube has a chamfer on the lower end and said voltage contrast plate is offset from said electron optical axis.
- 14. An electron beam column as in claim 1, further comprising a stage situated below said detector optics assembly and said secondary electron detector.
- 15. An electron beam column as in claim 1, wherein said probe optics assembly comprises:
an electron gun; an accelerating region situated below said electron gun; scanning deflectors situated below said accelerating region; and focusing lenses situated below said deflectors.
- 16. An electron beam column comprising:
a probe optics assembly, for forming an electron probe; an electron optical axis, defined by said probe optics assembly; a secondary electron detector situated below said probe optics assembly; and a field free tube with a chamfered lower end, situated between said probe optics assembly and said secondary electron detector.
- 17. An electron beam column as in claim 16, wherein said probe optics assembly comprises:
an electron gun; an accelerating region situated below said electron gun; scanning deflectors situated below said accelerating region; and focusing lenses situated below said deflectors.
- 18. An electron beam column comprising:
a probe optics assembly, for forming an electron probe; an electron optical axis, defined by said probe optics assembly; a secondary electron detector situated below said probe optics assembly; a field free tube with a chamfered lower end, situated between said probe optics and said secondary electron detector; and a voltage contrast plate offset from said electron optical axis, situated below said field free tube and said secondary electron detector.
- 19. An electron beam column as in claim 18, wherein said probe optics assembly comprises:
an electron gun; an accelerating region situated below said electron gun; scanning deflectors situated below said accelerating region; and focusing lenses situated below said deflectors.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/338,579 filed Apr. 18, 2001.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60338579 |
Apr 2001 |
US |