Dual-frequency laser interferometer vertical measurement optical path mirror adjustment device for lithography machine

Abstract

A dual-frequency laser interferometer vertical measurement optical path mirror adjustment device for a lithography machine belongs to the technical field of optical element adjustment; the device includes a mirror, a mirror seat, two adjustment foot assemblies, a fixed foot assembly, and a mirror It is bonded to the reflector base and compensates the gravitational deformation of the reflector through three tension springs. Two adjustment foot assemblies and one fixed foot assembly are installed on the reflector base. The anti-detachment screw on the top mounts the reflector base on the measurement frame, the adjustment of the reflector base relative to the measurement frame can be realized by adjusting the differential screw of the adjustment foot, and the adjustment of the reflector is realized; the invention has high adjustment accuracy, simple structure, and With locking function.

Description

technical field [0001] The invention belongs to the technical field of optical element adjustment, and mainly relates to a vertical measurement optical path reflector adjustment device for a dual-frequency laser interferometer of a lithography machine. Background technique [0002] In the lithography machine system, a laser interferometer is generally used to precisely measure the position in three directions of the wafer stage space. The measurement of the horizontal direction of the silicon wafer stage in the lithography machine, that is, the X and Y directions (in the lithography machine, the optical axis of the projection objective lens is generally defined as the Z direction of the coordinate system, and the direction perpendicular to the projection objective lens is the horizontal direction) can generally be measured. Make the beam of laser interferometer shoot horizontally to the side of the wafer stage and directly install the mirror on the side of the wafer stage to...

AI Technical Summary

Problems solved by technology

In addition, under the action of gravity, the long reflector will have serious self-deformation and affect the measurement accuracy, so the adjustment mechanism needs to compensate the gravity of the reflector

[0004] U.S. Patent US6020964 proposes a technical solution to directly install a plane reflector on the lower surface of the measurement frame to reflect the vertical measurement beam. This method lacks the mirror adjustment link, and cannot realize the adjustment of the position and attitude of the long reflector, and cannot guarantee the Z direction. measurement accuracy

US Patent No. 6285457B2 proposes a technical solution, which controls the movement of the mirror on the main frame by a motor, reflects the laser interferometer measurement light, and realizes the measurement light dynamic tracking of the X and Y positions of the vertical rectangular plane mirror on the stage, and finally realizes the vertical Measurement, this method is complicated to implement and introduces mechanical vibration, which affects the measurement accuracy

[0005] A mirror adjustment device is proposed in Chinese patent CN103149664A, which is designed with an adjustable shrapnel, the mirror seat is connected to the frame through the adjustment shrapnel, and the adjustment of the mirror can be realized by adjusting the screws on the shrapnel; in the Chinese patent CN201654310U An adjustment mechanism for the reflector is proposed, which adopts multi-point adjustment evenly distributed relative to the symmetry axis. The adjustment of the position of the reflector in the optical path can be realized by adjusting the coarse adjustment screw and the fine adjustment screw. However, due to the large number of adjustment screws, The actual adjustment process is relatively complicated; a three-degree-of-freedom mirror adjustment device is proposed in Chinese patent CN101216590, which uses the multi-degree-of-freedom working principle of the universal joint to realize the adjustment of the tilt and pitch of the mirror, and adjusts the base and the mirror frame by controlling The distance between them can be adjusted in three degrees of freedom, but the accuracy is difficult to guarantee through the adjustment of four adjustment pins; the above-mentioned patents use ordinary screws to realize the adjustment of the mirror, the actual adjustment accuracy is difficult to guarantee, and there is no lock after the adjustment is completed. Tight function, a little vibration may affect the adjustment result

Images