System and method for multi-beam electron microscopy using a detector array
A system and method of an electron multi-beam imaging system is disclosed. The system may include an imaging sub-system. The imaging sub-system may include one or more electron beam sources configured to generate a plurality of beamlets to simultaneously probe a plurality of measurement regions on a sample. The imaging sub-system may further include one or more electron optics configured to adjust the plurality of beamlets. The imaging sub-system may further include a detector array, where the detector array includes a plurality of detectors configured to detect electrons emanating from a measurement region of the sample. For the system and method, each detector may include a pass-through channel configured for receiving a beamlet of the plurality of beamlets.
1 . An electron multi-beam imaging system comprising:
an imaging sub-system comprising:
one or more electron beam sources configured to generate a plurality of beamlets to simultaneously probe a plurality of measurement regions on a sample;
one or more electron optics configured to adjust the plurality of beamlets; and
a detector array, wherein the detector array comprises a plurality of detectors, wherein each detector of the detector array includes a pass-through channel, wherein a respective pass-through channel is configured to receive a respective beamlet of the plurality of beamlets to the sample wherein each detector is configured to detect electrons emanating from a measurement region of the sample, wherein the detector array is actuatable between a first position and a second position, wherein the first position comprises a detecting position configured for detecting backscattered electrons emanating from the sample, wherein the second position comprises a retracted position.
2 . The electron multi-beam imaging system of claim 1 , wherein the electrons comprise backscattered electrons.
3 . The electron multi-beam imaging system of claim 1 , wherein the detector array is configured to be disposed between the one or more electron optics and the sample.
4 . The electron multi-beam imaging system of claim 1 , wherein the imaging sub-system is configured to detect secondary electrons using a secondary detector when the detector array is in the retracted position.
5 . The electron multi-beam imaging system of claim 1 , wherein the plurality of detectors are coplanar.
6 . The electron multi-beam imaging system of claim 1 , wherein each detector comprises a recess facing the sample.
7 . The electron multi-beam imaging system of claim 1 , wherein each detector comprises an active layer.
8 . The electron multi-beam imaging system of claim 7 , wherein the active layer comprises at least one of an n-type or a p-type material.
9 . The electron multi-beam imaging system of claim 8 , wherein the active layer comprises an aluminum coating layer.
10 . The electron multi-beam imaging system of claim 7 , wherein the active layer comprises a substrate layer, a p-type layer, and an n-type layer.
11 . The electron multi-beam imaging system of claim 7 , wherein the active layer comprises a cylindrical shape configured to be aligned with the beamlet when in a detecting position.
12 . The electron multi-beam imaging system of claim 11 , wherein the cylindrical shape is adjacent a cap on an end of the cylindrical shape, wherein the cap comprises the pass-through channel.
13 . The electron multi-beam imaging system of claim 11 , wherein the cylindrical shape comprises a scintillator layer.
14 . The electron multi-beam imaging system of claim 13 , wherein the scintillator layer comprises a distal end region and an inner cylindrical surface region.
15 . The electron multi-beam imaging system of claim 13 , wherein the detector further comprises a photocathode element.
16 . The electron multi-beam imaging system of claim 1 , wherein the detector comprises a capacitive sensor head configured to at least one of sense or control a position of the detector array relative to the sample.
17 . The electron multi-beam imaging system of claim 1 , further comprising: a controller configured to select a subset of the plurality of beamlets, the subset having a larger pitch than the plurality of beamlets.
18 . A method comprising:
generating electrons of a plurality of beamlets using one or more electron beam sources;
adjusting the plurality of beamlets using one or more electron optics configured to receive the plurality of beamlets;
receiving each beamlet of the plurality of beamlets through a pass-through channel of a respective detector of a detector array;
illuminating, for each beamlet, a measurement region of a sample;
collecting, for each beamlet, electrons emanating from the measurement region using the respective detector; and
detecting the electrons using the respective detector;
actuating the detector array from a second position to a first position, wherein the first position comprises a detecting position configured for detecting the electrons emanating from the sample, wherein the second position comprises a retracted position.
19 . The method of claim 18 , wherein the electrons comprise backscattered electrons.
20 . The method of claim 18 , wherein the detector array is disposed between the one or more electron optics and the sample during the detecting of the electrons using the respective detector.
21 . The method of claim 18 , further comprising:
detecting secondary electrons using a secondary detector when the detector array is in the retracted position.
22 . The method of claim 18 , further comprising:
selecting a subset of the plurality of beamlets, the subset having a larger pitch than the plurality of beamlets.