Method for evaluating secondary optical system of electron beam inspection device

1. A method for evaluating a secondary optical system of an electron beam inspection device provided with a primary optical system that irradiates a sample placed at an observation target position with an electron beam emitted from an electron source, and the secondary optical system that forms, on a detector, an enlarged image of an electron beam emitted from said sample or an electron beam transmitted through said sample, the method comprising:

placing not said sample but a photoelectric surface on which a predetermined pattern is formed at the observation target position; irradiating the photoelectric surface with laser light; forming an enlarged image of an electron beam emitted from the photoelectric surface on the detector by the secondary optical system; comparing a pattern of the electron beam image obtained by the detector with the predetermined pattern formed on the photoelectric surface to measure a distortion of the pattern of the electron beam image obtained by the detector; and evaluating the secondary optical system based on the measured distortion of the pattern of the electron beam image obtained by the detector.

2. The method according to claim 1 , wherein a predetermined pattern is formed on the photoelectric surface.

3. The method according to claim 1 , wherein the secondary optical system has an objective lens and an imaging lens arranged between the objective lens and the detector.

4. The method according to claim 2 , wherein the secondary optical system has an objective lens and an imaging lens arranged between the objective lens and the detector.

5. The method according to claim 3 , wherein the photoelectric surface is irradiated with the laser light from a side opposite to a position of the objective lens.

6. The method according to claim 4 , wherein the photoelectric surface is irradiated with the laser light from a side opposite to a position of the objective lens.

7. The method according to claim 1 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

8. The method according to claim 2 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

9. The method according to claim 3 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

10. The method according to claim 4 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

11. The method according to claim 5 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

12. The method according to claim 6 , wherein the photoelectric surface disposed in a chamber is irradiated with the laser light in a state where a lens barrel of the primary optical system is separated from a lens barrel of the secondary optical system.

13. The method according to claim 1 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

14. The method according to claim 2 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

15. The method according to claim 3 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

16. The method according to claim 4 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

17. The method according to claim 5 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

18. The method according to claim 6 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.

19. The method according to claim 7 , wherein the laser light is emitted from a laser source arranged outside a chamber and transmitted through a view port provided on the chamber, and the photoelectric surface disposed in the chamber is irradiated with the laser light.