Secondary electron detector for ion beam systems
Dual beam charged particle microscopy systems, sensors, and techniques are disclosed. A charged particle microscope system can include a vacuum chamber, a sample stage disposed in the vacuum chamber, a first beam source operable to direct a first particle beam into the vacuum chamber, a second beam source operable to direct a second particle beam into the vacuum chamber, a first charged particle sensor, and a second charged particle sensor. The first charged particle sensor can include a detector cell having a semiconductor layer characterized by a bandgap equal to or greater than about 2.0 eV, oriented to detect secondary electrons generated based on an interaction between the first particle beam or the second particle beam and the sample. The second charged particle sensor can include a scintillator detector configured to be saturated from electrons generated based on an interaction between the second particle beam and the sample.
1 . A charged particle microscope system comprising:
a vacuum chamber;
a sample stage disposed in the vacuum chamber and configured to receive a sample to be tested in the vacuum chamber;
a first beam source operable to direct a first particle beam into the vacuum chamber toward the sample stage;
a second beam source operable to direct a second particle beam into the vacuum chamber toward the sample stage;
a first charged particle sensor disposed at a first location in the vacuum chamber and comprising a detector cell, the detector cell having a semiconductor layer electrically biased across at a first level and characterized by a bandgap equal to or greater than about 2.0 eV, and the first charged particle sensor oriented to detect secondary electrons generated based on an interaction between the first particle beam or the second particle beam and a sample disposed on the sample stage; and
a second charged particle sensor disposed at a second location in the vacuum chamber and comprising a scintillator detector electrically biased at a second level greater than the first level, the second charged particle sensor configured to be saturated from electrons generated based on an interaction between the second particle beam and the sample disposed on the sample stage.
2 . The charged particle microscope system of claim 1 , wherein the first level is about 1 kV.
3 . The charged particle microscope system of claim 1 , wherein the second level is about 10 kV.
4 . The charged particle microscope system of claim 1 , wherein the first location is closer to the sample stage than the second location.
5 . The charged particle microscope system of claim 1 , wherein a distance between the first location and the sample stage is about 7 mm to about 10 cm.
6 . The charged particle microscope system of claim 1 , wherein a distance between the second location and the sample stage is about 10 cm.
7 . The charged particle microscope system of claim 1 , wherein the semiconductor layer comprises one or more materials selected from a group consisting of silicon carbide, single crystalline diamond, polycrystalline diamond, gallium nitride, gallium phosphide, cadmium sulfide, aluminum phosphide, zinc selenide, zinc sulfide, and aluminum nitride.
8 . The charged particle microscope system of claim 1 , wherein the first particle beam is an electron beam.
9 . The charged particle microscope system of claim 1 , wherein the second particle beam is an ion beam, or wherein the second particle beam is a laser beam.
10 . The charged particle microscope system of claim 9 , wherein the ion beam is configured for milling or polishing.