Charged particle beam device and charged particle beam device calibration method
Provided is a charged particle beam device and a charged particle beam device calibration method capable of correcting an influence of characteristic variation and noise with high accuracy. Control units execute a first calibration of correcting a characteristic variation between a plurality of channels in detectors and signal processing circuits by using a setting value of a control parameter for each of the plurality of channels in a state in which a primary electron beam is not emitted. The control units further execute a second calibration of correcting a characteristic variation between the plurality of channels in scintillators or the like by using the setting value of the control parameter for each of the plurality of channels in a state in which the primary electron beam is emitted.
1. A charged particle beam device, comprising:
detection systems of a plurality of channels; and
a control unit configured to control characteristics of the detection systems of the plurality of channels by using a setting value of a control parameter, wherein
each of the detection systems of the plurality of channels includes:
a detector configured to detect charged particles discharged from a sample in response to irradiation of a charged particle beam,
an optical component arranged at a stage preceding to the detector, and
a signal processing circuit configured to process a detection signal from the detector, and
the control unit is configured to execute:
a first calibration of correcting a characteristic variation between the plurality of channels in the detector and the signal processing circuit by using the setting value of the control parameter for each of the plurality of channels in a state in which the charged particle beam is not emitted, and
a second calibration of correcting a characteristic variation between the plurality of channels in the optical component by using the setting value of the control parameter for each of the plurality of channels in a state in which the charged particle beam is emitted.
2. The charged particle beam device according to claim 1 , further comprising:
an image processing unit configured to generate an image based on an output signal from the signal processing circuit of each of the plurality of channels, wherein
the control unit is configured to:
store first device data in a memory, the first device data including an image for each of the plurality of channels generated via the image processing unit as a result of the first calibration and the setting value of the control parameter associated with the image,
store second device data in a memory, the second device data including an image for each of the plurality of channels generated via the image processing unit as a result of the second calibration and the setting value of the control parameter associated with the image, and
output the first device data and the second device data to an outside of the device.
3. The charged particle beam device according to claim 2 , further comprising:
a screen display unit configured to display the first device data and the second device data on a screen.
4. The charged particle beam device according to claim 1 , wherein
at a time of the second calibration, the control unit emits the charged particle beam in a state in which the setting value of the control parameter obtained in the first calibration is reflected in the detection systems of the plurality of channels.
5. The charged particle beam device according to claim 4 , wherein
the control unit is configured to:
search for the setting value of the control parameter at a time of the first calibration, the setting value of the control parameter including a gain and an offset value for the detector and the signal processing circuit and a threshold value for removing a dark pulse from the detector, and
search for the setting value of the control parameter at the time of the second calibration, the setting value of the control parameter including a gain and an offset value for the detector and the signal processing circuit, a threshold value for removing a dark pulse from the detector, and a correction coefficient in a load regulation correction for correcting an amplitude reduction of the detection signal from the detector.
6. A charged particle beam device, comprising:
a detector configured to detect charged particles discharged from a sample in response to irradiation of a charged particle beam;
an optical component arranged at a stage preceding to the detector;
a signal processing circuit configured to process a detection signal from the detector; and
a control unit configured to control characteristics of the detector and the signal processing circuit using a setting value of a control parameter, wherein
the control unit is configured to execute a first calibration of searching for a setting value of the control parameter in a state in which the charged particle beam is not emitted, and a second calibration of searching for a setting value of the control parameter in a state in which the charged particle beam is emitted.
7. The charged particle beam device according to claim 6 , wherein
at a time of the second calibration, the control unit emits the charged particle beam in a state in which the setting value of the control parameter obtained in the first calibration is reflected.
8. The charged particle beam device according to claim 6 , further comprising:
an image processing unit configured to generate an image based on an output signal from the signal processing circuit, wherein
the control unit is configured to:
store first device data in a memory, the first device data including an image generated via the image processing unit as a result of the first calibration and the setting value of the control parameter associated with the image,
store second device data in a memory, the second device data including an image generated via the image processing unit as a result of the second calibration and the setting value of the control parameter associated with the image, and
output the first device data and the second device data to an outside of the device.
9. A charged particle beam device calibration method, the charged particle beam device including: detection systems of a plurality of channels each including a detector configured to detect charged particles discharged from a sample in response to irradiation of a charged particle beam; an optical component arranged at a stage preceding to the detector; and a signal processing circuit configured to process a detection signal from the detector, the charged particle beam device calibration method comprising:
performing a first calibration of correcting a characteristic variation between the plurality of channels in the detector and the signal processing circuit by using a setting value of a control parameter for each of the plurality of channels in a state in which the charged particle beam is not emitted; and
performing a second calibration of correcting a characteristic variation between the plurality of channels in the optical component by using a setting value of the control parameter for each of the plurality of channels in a state in which the charged particle beam is emitted.
10. The charged particle beam device calibration method according to claim 9 , further comprising:
generating an image based on an output signal of the signal processing circuit for each of the plurality of channels as a result of the first calibration, and storing the image and the setting value of the control parameter associated with the image in a memory as first device data;
generating an image based on an output signal of the signal processing circuit for each of the plurality of channels as a result of the second calibration, and storing the image and the setting value of the control parameter associated with the image in a memory as second device data; and
outputting the first device data and the second device data to an outside of the device.
11. The charged particle beam device calibration method according to claim 9 , further comprising:
at a time of the second calibration, emitting the charged particle beam in a state in which the setting value of the control parameter obtained in the first calibration is reflected in the detection systems of the plurality of channels.
12. The charged particle beam device calibration method according to claim 11 , further comprising:
searching for the setting value of the control parameter at a time of the first calibration, the setting value of the control parameter including a gain and an offset value for the detector and the signal processing circuit, and a threshold value for removing a dark pulse from the detector; and
searching for the setting value of the control parameter at the time of the second calibration, the setting value of the control parameter including a gain and an offset value for the detector and the signal processing circuit, a threshold value for removing a dark pulse from the detector, and a correction coefficient in a load regulation correction for correcting an amplitude reduction of the detection signal from the detector.
13. The charged particle beam device calibration method according to claim 12 , further comprising:
performing the first calibration and the second calibration each time the sample is changed.