Light path alignment device of laser interferometer and method

Abstract

The invention relates to a light path alignment device of a laser interferometer and a method. Laser emitted by a laser device is adjusted by a reflective mirror adjusting mechanism and is then transmitted into the laser interferometer, a polarization beam-splitting mirror divides the laser into reference light and measurement light, the reference light is reflected by a reference reflective mirror, the measurement light is reflected by a measurement reflective mirror, is transmitted to the polarization beam-splitting mirror and is then reflected by the polarization beam-splitting mirror to the optical fiber receiving head, and the beam-splitting mirror divides incident light into two parts, wherein the majority of the light is compressed by a compression lens component in the optical fiber receiving head and is transmitted to a receiver, and the rest of the light is projected to a light spot observation device for observation of overlapping of a reference light spot and a measurementlight spot.

Description

technical field [0001] The invention relates to the field of lithography, in particular to an interferometer optical path alignment device used for a lithography device. Background technique [0002] At present, laser interferometry has been widely used in high-precision position measurement, which has the characteristics of high precision, strong reliability, and small error interference. The alignment accuracy of the optical path of the laser interferometer will directly affect the measurement accuracy and measurement range of the interferometer. [0003] Agilent and Zygo companies in the United States proposed that the alignment accuracy of the optical path of the interferometer is mainly to observe the coincidence of the reference spot and the measurement spot in the exit spot of the interferometer. The traditional method is to adjust the laser or reflector without installing the optical fiber receiving head, and then install the image 3 The fiber optic receiver shown ...

AI Technical Summary

Problems solved by technology

However, when the position of the interferometer or the measuring mirror changes, the coincidence of the reference spot and the measuring spot will change, and it is necessary to readjust the coincidence of the reference spot and the measuring spot. At this time, the optical fiber receiving head must be removed

On the one hand, due to the limitation of the installation space of the interferometer, it is very difficult to disassemble and assemble the fiber receiving head, especially when it is applied in a scene with a small space such as a lithography machine; However, the optical fiber is easily damaged by frequent plugging and unplugging, which affects the service life of the optical fiber.

Images