Radiation analysis system, charged particle beam system, and radiation analysis method

Patent metadata

Field	Value
Publication number	US-12078763-B2
Application number	US-202017917200-A
Country	US
Kind code	B2
Filing date	Apr 30, 2020
Priority date	Apr 30, 2020
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

This radiation analysis system comprises a transition edge sensor that detects radiation, a current detection mechanism that detects a current flowing in the transition edge sensor, and a computer sub-system that processes a current detection signal from the current detection mechanism. The computer sub-system is characterized by executing: a process for calculating a baseline current of the current detection signal; a process for calculating a wave height value of a signal pulse produced in the detection signal when the transition edge sensor has detected radiation; a process for acquiring correlation data based on the baseline current and the wave height value; and a process for correcting the wave height value of the signal pulse, or an energy value calculated from the wave height value, on the basis of the correlation data and the baseline current from before production of the signal pulse when radiation having unknown energy is detected.

First claim

The invention claimed is:

1. A radiation analysis system comprising:
a superconductive transition edge sensor that detects a radiation;
a current detection mechanism that detects a current flowing through the superconductive transition edge sensor; and
a computer subsystem that processes a detection signal of the current from the current detection mechanism,
wherein the computer subsystem performs
a process of calculating a baseline current of the detection signal of the current,
a process of calculating a peak value of a signal pulse generated in the detection signal when the superconductive transition edge sensor detects the radiation,
a process of acquiring correlation data based on the baseline current and the peak value when a radiation having at least a first energy is detected by the superconductive transition edge sensor under two or more different temperature conditions, and
a process of correcting the peak value of the signal pulse or an energy value calculated from the peak value on the basis of the baseline current before the signal pulse is generated when a radiation having unknown energy is detected by the superconductive transition edge sensor and the correlation data.

2. The radiation analysis system according to claim 1 ,
wherein the computer subsystem further performs
calculating the unknown energy on the basis of the corrected peak value.

3. The radiation analysis system according to claim 1 ,
wherein, in the process of acquiring the correlation data, the computer subsystem acquires the correlation data based on the baseline current and the peak value when a radiation having multiple energies is detected by the superconductive transition edge sensor respectively under the two or more different temperature conditions.

4. The radiation analysis system according to claim 1 , further comprising:
a cold head for cooling the superconductive transition edge sensor; and
a heater provided to the cold head.

5. The radiation analysis system according to claim 4 ,
wherein the computer subsystem further performs
a process of controlling an output of the heater.

6. The radiation analysis system according to claim 5 ,
wherein, in the process of acquiring the correlation data, the computer subsystem controls the output of the heater so that a temperature variation in the cold head is equal to or smaller than ±0.1 mK.

7. The radiation analysis system according to claim 6 ,
wherein, in the process of acquiring the correlation data, the computer subsystem controls the output of the heater so that a variation of the baseline current is equal to or smaller than ±0.2 μA.

8. The radiation analysis system according to claim 5 ,
wherein the computer subsystem controls the output of the heater so that a variation of the baseline current is equal to or smaller than ±2.0 μA.

9. The radiation analysis system according to claim 1 ,
wherein the computer subsystem comprises a display unit, and
wherein the computer subsystem displays a GUI screen for acquiring the correlation data on the display unit.

10. The radiation analysis system according to claim 1 ,
wherein the current detection mechanism comprises
a superconducting quantum interference device amplifier, and
a room temperature amplifier for amplifying and forming an electric signal output from the superconducting quantum interference device amplifier.

11. A charged particle beam system comprising a radiation analysis system according to claim 1 .

12. A radiation analysis method comprising:
detecting a radiation by a superconductive transition edge sensor;
detecting a current flowing through the superconductive transition edge sensor by a current detection mechanism;
processing a detection signal of the current from the current detection mechanism;
calculating a baseline current of the current by a computer system;
calculating, by the computer system, a peak value of a signal pulse generated in the detection signal when the superconductive transition edge sensor detects the radiation;
acquiring, by the computer system, correlation data based on the baseline current and the peak value when a radiation having at least a first energy is detected by the superconductive transition edge sensor under two or more different temperature conditions, and
correcting, by the computer system, the peak value of the signal pulse or an energy value calculated from the peak value on the basis of the baseline current before the signal pulse is generated when a radiation having unknown energy is detected by the superconductive transition edge sensor and the correlation data.

13. A radiation analysis system comprising:
a superconductive transition edge sensor that detects a radiation;
a current detection mechanism that detects a current flowing through the superconductive transition edge sensor; and
a computer subsystem that processes a detection signal of the current from the current detection mechanism,
wherein the computer subsystem comprises a storage device that stores therein correlation data based on a baseline current and a peak value when a radiation having at least a first energy is detected by the superconductive transition edge sensor under two or more different temperature conditions, and
wherein the computer subsystem performs
a process of calculating a baseline current of the detection signal of the current,
a process of calculating a peak value of a signal pulse generated in the detection signal when the superconductive transition edge sensor detects the radiation, and
a process of correcting the peak value of the signal pulse or an energy value calculated from the peak value on the basis of the baseline current before the signal pulse is generated when a radiation having unknown energy is detected by the superconductive transition edge sensor and the correlation data.

14. A radiation analysis system comprising:
a superconductive transition edge sensor that detects a radiation;
a current detection mechanism that detects a current flowing through the superconductive transition edge sensor; and
a computer subsystem that processes a detection signal of the current from the current detection mechanism,
wherein the computer subsystem performs
a process of calculating a baseline current of the detection signal of the current,
a process of calculating a peak value of a signal pulse generated in the detection signal when the superconductive transition edge sensor detects the radiation,
a process of acquiring correlation data based on the baseline current and the peak value, and
a process of calculating, if the baseline current before the signal pulse is generated when a radiation having unknown energy is detected by the superconductive transition edge sensor exceeds a threshold, an average value of the baseline currents from before a first point to a second point before a point that exceeds the threshold, and correcting the peak value of the signal pulse or an energy value calculated from the peak value on the basis of the average value of the baseline currents and the correlation data.

Assignees

• Hitachi High Tech Corp

Inventors

• Takano Akira
• Tanaka Keiichi

Classifications

• G01N2223/507

  secondary-emission detector · CPC title

• G01N2223/418

  electron microscope · CPC title

• G01N2223/07

  secondary emission · CPC title

• G01N23/2251

  using incident electron beams, e.g. scanning electron microscopy [SEM] · CPC title

• H01J2237/24495

  Signal processing, e.g. mixing of two or more signals · CPC title