Charged particle beam apparatus
Light which is radiant energy is emitted from a sample which is heated, and is detected by a backscattered electron detector. A detection signal from the backscattered electron detector includes a radiant component. A radiant component removal section extracts the radiant component from the detection signal using a filter, and then removes the radiant component from the detection signal. An optical detector which detects the radiant component may be provided. A divided detector may be provided as the backscattered electron detector.
1. A charged particle beam apparatus comprising:
equipment that illuminates a sample with a charged particle beam;
a detector that detects a particle of interest emitted from the sample, caused by illumination of the charged particle beam, and that outputs a detection signal comprising a radiant component caused by detection of radiant energy emitted from a heated subject, caused by heating of the sample;
an identifier that identifies the radiant component through a processing of the detection signal or through selective detection of the radiant energy;
a remover that removes the radiant component from the detection signal; and
a generator that generates an image representing the sample based on a detection signal from which the radiant component is removed.
2. The charged particle beam apparatus according to claim 1 , wherein
the charged particle beam is an electron beam,
the particle of interest is a backscattered electron or a secondary electron emitted from the sample, and
the detection of the radiant energy is detection of light.
3. The charged particle beam apparatus according to claim 1 , wherein
the identifier comprises a filter which extracts the radiant component from the detection signal.
4. The charged particle beam apparatus according to claim 3 , wherein
the charged particle beam is two-dimensionally scanned over an observation region which is set on the sample,
the detection signal is a one-dimensional signal acquired through the two-dimensional scanning of the charged particle beam,
the filter is a one-dimensional filter, and
the filter is one-dimensionally scanned with respect to the detection signal.
5. The charged particle beam apparatus according to claim 3 , wherein
the filter is a filter which realizes a smoothing action.
6. The charged particle beam apparatus according to claim 3 , wherein
the detector has a plurality of detection regions sensitive to the particle of interest and to the radiant energy,
a plurality of detection signals are output from the plurality of detection regions in parallel with each other,
the charged particle beam apparatus further comprises:
a plurality of adjusters that individually apply gain adjustment and offset adjustment on the plurality of detection signals, and that output a plurality of detection signals after adjustment in parallel with each other; and
a summation device that adds the plurality of detection signals after adjustment and that outputs a detection signal after summation, and
the detection signal after summation is input to the filter.
7. The charged particle beam apparatus according to claim 3 , wherein
the detector has a plurality of detection regions sensitive to the particle of interest and to the radiant energy,
a plurality of detection signals are output from the plurality of detection regions in parallel with each other, and
the identifier extracts a plurality of radiant component candidates from the plurality of detection signals, and identifies the radiant component based on the plurality of radiant component candidates.
8. The charged particle beam apparatus according to claim 7 , wherein
the remover removes the radiant component from the plurality of detection signals, and
the generator generates the image representing the sample based on a plurality of detection signals from which the radiant component is removed.
9. The charged particle beam apparatus according to claim 1 , wherein
the detector is a primary detector,
the detection signal is a primary detection signal,
the identifier comprises a sub detector which selectively detects the radiant energy without detecting the particle of interest, and
the radiant component is identified based on a sub detection signal which is output from the sub detector.
10. The charged particle beam apparatus according to claim 9 , wherein
the sub detector has an incidence film which permits the radiant energy to transmit and which blocks the particle of interest.
11. The charged particle beam apparatus according to claim 9 , wherein
a plurality of primary detection regions functioning as the primary detector are provided,
the remover removes the radiant component from a plurality of primary detection signals which are output from the plurality of primary detection regions, and
the generator generates the image representing the sample based on a plurality of primary detection signals from which the radiant component is removed.