Charged particle beam application system
View Patent ↗An object of the present invention is to measure a landing angle even in a multi electron beam lithography system in which current amount of each beam is small. Another object thereof is to measure an absolute value of the landing angle and a relative landing angle with the high SN ratio. In a transmission detector including two diaphragm plates (first and second diaphragms) and a detector, a detection angle determined by a distance between the first and second diaphragms and an aperture diameter of the second diaphragm is made equal to or smaller than the divergence angle of the electron beam to be measured, and the landing angle is determined based on the relation between a center of the fine hole of the first diaphragm and the center of the aperture of the second diaphragm at which the amount of detected current is maximum.
1. A charged particle beam application system, comprising:
a charged particle source;
a charged particle lens for converging charged particle beam emitted from said charged particle source;
a stage for placing an object to which said charged particle beam is irradiated; and
means for measuring a landing angle of said charged particle beam.
2. The charged particle beam application system according to claim 1 ,
wherein said means for measuring the landing angle includes a charged particle beam detector, and
the landing angle and/or a convergence angle are obtained from the amount of charged particles detected by said charged particle beam detector.
3. The charged particle beam application system according to claim 1 ,
wherein a detection system including a first diaphragm, a second diaphragm, and a charged particle beam detector is provided, and
an angle determined by a distance between said first diaphragm and said second diaphragm and an aperture diameter of said second diaphragm is almost equal to or smaller than a convergence angle of said charged particle beam near said detection system.
4. The charged particle beam application system according to claim 3 , further comprising:
a function to measure the amount of charged particles passing through said first diaphragm and said second diaphragm and feed back the measurement result to lens conditions and deflector conditions.
5. The charged particle beam application system according to claim 3 ,
wherein the angle determined by a distance between said first diaphragm and said second diaphragm and an aperture diameter of said second diaphragm is variable.
6. The charged particle beam application system according to claim 3 ,
wherein a hole of said first diaphragm is larger than a diameter of the charged particle beam at a position of said first diaphragm.
7. The charged particle beam application system according to claim 1 ,
wherein a detection system including a first diaphragm, a second diaphragm, and a charged particle beam detector is provided, and
said first diaphragm has a plurality of holes arranged at even intervals.
8. The charged particle beam application system according to claim 7 ,
wherein said plurality of holes are arranged in a lattice.
9. The charged particle beam application system according to claim 7 ,
wherein pitch of said plurality of holes is shorter than an aperture diameter of said second diaphragm.
10. The charged particle beam application system according to claim 7 ,
wherein an entire size of said plurality of holes is larger than the aperture of said second diaphragm.
11. The charged particle beam application system according to claim 1 ,
wherein a detection system including a first diaphragm, a second diaphragm, and a charged particle beam detector is provided, and
a relative position of said first diaphragm and said second diaphragm can be mechanically moved.
12. The charged particle beam application system according to claim 11 ,
wherein a minimum unit length of the mechanical movement of said relative position is shorter than the aperture diameter of said second diaphragm.
13. The charged particle beam application system according to claim 11 ,
wherein a maximum movable length of the mechanical movement of said relative position is longer than the aperture diameter of said second diaphragm.
14. The charged particle beam application system according to claim 1 ,
wherein a detection system including a first diaphragm, a second diaphragm, and a charged particle beam detector is provided, and
a deflector is provided between said first diaphragm and said second diaphragm.
15. The charged particle beam application system according to claim 14 ,
wherein said deflector functions also as said first diaphragm.
16. The charged particle beam application system according to claim 14 ,
wherein a deflectable length by said deflector is longer than the aperture diameter of said second diaphragm.
17. The charged particle beam application system according to claim 1 ,
wherein a detection system including a first diaphragm, a second diaphragm, and a charged particle beam detector is provided, and
a current passing through said first diaphragm and said second diaphragm is measured under different charged particle beam conditions.
18. The charged particle beam application system according to claim 17 ,
wherein said different charged particle beam conditions are different multi beams.
19. The charged particle beam application system according to claim 17 ,
wherein said different charged particle beam conditions are the deflection amount of the beam.