Apparatus and method including a direct bombardment detector and a secondary detector for use in electron microscopy
View Patent ↗An apparatus for use with an electron beam for imaging a sample. The apparatus has a down-conversion detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample, a direct bombardment detector adjacent to the down-conversion detector and configured to detect the electron microscopy signal, and a mechanism selectively exposing the down-conversion detector and the direct bombardment detector to the electron microscopy signal. A method using the apparatus is also provided.
1. An apparatus for use with an electron beam for imaging a sample, the apparatus comprising:
a down-conversion detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;
a direct bombardment detector adjacent to the down-conversion detector and configured to detect the electron microscopy signal; and
a mechanism selectively exposing the direct bombardment detector to the electron microscopy signal.
2. The apparatus of claim 1 , wherein the down-conversion detector comprises a scintillator.
3. The apparatus of claim 2 , wherein the scintillator includes a YAG scintillator.
4. The apparatus of claim 2 , wherein the scintillator includes a polycrystalline scintillator.
5. The apparatus of claim 1 , wherein the down-conversion detector comprises a plurality of pixels.
6. The apparatus of claim 1 , wherein the down-conversion detector includes a charge-coupled device (CCD).
7. The apparatus of claim 1 , wherein the down-conversion detector includes a CMOS image sensor.
8. The apparatus of claim 1 , wherein the down-conversion detector is configured to focus the electron microscopy signal.
9. The apparatus of claim 1 , wherein the down-conversion detector is configured to identify of a region of interest of the sample.
10. The apparatus of claim 1 , wherein the direct bombardment detector comprises a plurality of active pixel sensors.
11. The apparatus of claim 1 , wherein the mechanism comprises a shutter positionable in a propagation path of the electron microscopy signal upstream to the direct bombardment detector.
12. The apparatus of claim 1 , wherein the mechanism comprises a steering device to steer the electron microscopy signal between the down-conversion detector and the direct bombardment detector.
13. The apparatus of claim 1 , wherein the down-conversion detector and the direct bombardment detector are integrated into a single camera.
14. The apparatus of claim 1 , further comprising an optical fiber plate coupled to the down-conversion detector.
15. The apparatus of claim 1 , further comprising a Faraday plate configured to measure total cumulative dose of the electron microscopy signal.
16. The apparatus of claim 1 , further comprising a Faraday plate configured to measure instantaneous dose of the electron microscopy signal.
17. A apparatus for use with an electron beam for imaging a sample, the apparatus comprising:
a down-conversion detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;
a direct bombardment detector adjacent to the down-conversion detector and configured to detect the electron microscopy signal; and
wherein the down-conversion detector and the direct bombardment detector are integrated into a single camera.
18. A method of producing an image of a sample using an electron beam, the method comprising the steps of:
a) applying the electron beam to the sample for generating an electron microscopy signal;
b) detecting the electron microscopy signal by a down-conversion detector to obtain a detection result;
c) determining at least one detection parameter based on the detection result of the down-conversion detector; and
d) detecting the electron microscopy signal by a direct bombardment detector using the detection parameter.
19. The method of claim 18 , wherein the sample includes a biological matter.
20. The method of claim 18 , wherein the detection parameter includes focusing information of the electron microscopy signal.
21. The method of claim 18 , wherein the detection parameter includes a region of interest of the sample.
22. The method of claim 18 , further comprising a step of steering the electron microscopy signal towards the direct bombardment detector for detecting the electron microscopy signal by the direct bombardment detector.
23. The method of claim 18 , further comprising a step of blocking the direct bombardment detector from exposure of the electron microscopy signal before the detection parameter is determined.
24. The method of claim 18 , further comprising a step of cooling the down-conversion detector to below ambient temperature.
25. The method of claim 18 , further comprising a step of cooling the direct bombardment detector to below ambient temperature.
26. An apparatus for use with an electron beam for imaging a sample, the apparatus comprising:
a direct bombardment detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;
a beam current measuring device to be located adjacent to the direct bombardment detector; and
a mechanism configured to selectively prevent the electron microscopy signal from being incident on the direct bombardment detector.
27. The apparatus of claim 26 , wherein the beam current measuring device includes a Faraday plate.
28. The apparatus of claim 26 , wherein the mechanism includes a shutter positionable in the propagation path of the electron microscopy signal upstream to the direct bombardment detector.
29. A method of producing an image of a sample using an electron beam and a direct bombardment detector, the method comprising the step of:
a) applying the electron beam to the sample for generating an electron microscopy signal;
b) detecting the electron microscopy signal by a beam current detector to obtain a detection result;
c) determining at least one detection parameter based on the detection result of the beam current detector; and
d) detecting the electron microscopy signal by the direct bombardment detector using the detection parameter.
30. The method of claim 29 , wherein the sample includes a biological matter.
31. The method of claim 29 , wherein the detection parameter includes a dose of the electron microscopy signal.
32. The method of claim 31 , wherein the dose includes an instantaneous dose applied to the direct bombardment detector.
33. The method of claim 31 , wherein the dose includes a total cumulative dose applied to the direct bombardment detector.
34. The method of claim 29 , further comprising a step of setting a dose of the electron beam applied to the sample.
35. The method of claim 29 , further comprising a step of positioning a moveable shutter to selectively block the electron microscopy signal from the direct bombardment detector based on the detection parameter.