US 12,412,728 B2
Electron beam inspection system
Ryuichi Kusakabe, Tokyo (JP); and Noriyuki Kobayashi, Tokyo (JP)
Assigned to JEOL Ltd., Tokyo (JP)
Filed by JEOL Ltd., Tokyo (JP)
Filed on Jun. 20, 2022, as Appl. No. 17/844,120.
Claims priority of application No. 2021-102160 (JP), filed on Jun. 21, 2021.
Prior Publication US 2022/0406560 A1, Dec. 22, 2022
Int. Cl. H01J 37/20 (2006.01)
CPC H01J 37/20 (2013.01) [H01J 2237/20278 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An electron beam inspection system comprising:
an electron beam source for emitting an electron beam;
a stage mechanism for providing movable support of a sample irradiated with the electron beam; and
a pump for supplying air to the stage mechanism;
wherein said stage mechanism has a guide shaft having a partition formed on a surface thereof, a slider having a pressure chamber that is partitioned into a first pressure subchamber and a second pressure subchamber by the partition and movably supported to the guide shaft via a hydrostatic bearing, a first servo valve operative to control the pressure in the first pressure subchamber, a second servo valve operative to control the pressure in the second pressure subchamber, a first exhaust pipe through which air from the first servo valve passes, a second exhaust pipe through which air from the second servo valve passes, and an exhaust valve mounted in the first exhaust pipe;
wherein the exhaust valve is opened when the first and second servo valves are in operation and the exhaust valve is closed when supply of electric power to the first and second servo valves is cut off such that the first exhaust pipe is closed and the second exhaust pipe is open creating a higher pressure in the first pressure subchamber connected to the first servo valve than the pressure in the second pressure subchamber connected to the second servo valve, thereby causing the slider to retract into a safety position where the slider is prevented from moving in a manner contrary to a user's intention and the slider is moved relative to the partition formed on the guide shaft and partitioning the first pressure subchamber and the second pressure subchamber;
wherein the slider of the stage mechanism floats out of contact with the guide shaft even when a supply of electric power is cut off;
wherein said first exhaust pipe branches into an exhaust pipe and an adjusting pipe;
wherein said exhaust valve is mounted in the exhaust pipe; and
wherein an exhaust flow adjusting mechanism for adjusting the flow rate of air passing through the exhaust pipe is mounted in the adjusting pipe.