The Two Dimensional Nanometer Displacement Stage With Heavy Load And Large Hollow Aperture

The semiconductor industry has developed rapidly and has entered the nanoscale era.To solve the problem of accurately measuring the line width of the mask and tracing its value to the international unit of length,the National Institute of Metrology China has designed a ultraviolet microscope.High precision positioning was needed by the two dimensional nanometer displacement stage which applied to the ultraviolet device will directly carry the mask.In this paper,a two dimensional nanometer displacement stage with heavy load and large hollow aperture for UV optical microscope was designed.The main research contents were as follows:(1)The necessity of the research on two dimensional nanometer displacement stage with heavy load and large hollow aperture was studied.According to the needs of ultraviolet device,the technical indexes of displacement table were determined.(2)The design of two dimensional nanometer displacement stage with heavy load and large hollow aperture was completed.In order to achieve the two dimensional nanometer displacement,the piezoelectric ceramics were used as displacement actuators,and the flexible hinges were used as motion actuators,and the superimposed branches were used as flexible guide mechanisms.Due to the nested structure of frames,the stage could realize two dimensional motion.The displacement measurement is accomplished by laser interferometry.The structural design of the displacement stage was completed above.(3)The performances of the stage were theoretically analyzed and verified by finite element method.In order to analyze the displacement performance,the theoretical formulas of stage stiffness,coupling stiffness,angular adjustment,hinge stress and natural frequency were deduced by modeling the stage.Use the finite element analysis method to verify the theoretical formula and analyzed the load-bearing performance.The structural parameters were determined according to the needs.(4)The test system was designed and built to test the performances of the displacement stage and analyze the experimental results.In order to improve the performance of the stage,the displacement compensation was performed and the coupling displacement and the angle pendulum were corrected.The experimental results show that the effect of the compensation and correction was good,the displacement stage meets the needs and the design was reliable.