Nanopositioning X–Y stage with an embedded Six-DOF error compensation system based on Abbe and Bryan principles

Abstract

Nanoprecision positioning stages are essential components in ultra-precision manufacturing and measurement equipment such as lithography machines and nanocoordinate measuring machines. Embedded geometrical error measurements are becoming more important in the X–Y stages of nanoprecision positioning for accuracy improvement through real-time error compensation. In this study, a high-precision X–Y positioning stage conforming to the Abbe principle is developed using a self-developed real-time embedded six degree-of-freedom feedback system (6DFS). The 6DFS comprises three miniature laser interferometers for X–Y positioning and two dual-angle autocollimators for pitch, yaw, and roll angle measurements. Another laser interferometer is employed to measure the Z-straightness error and compensate for it based on the Bryan principle. The systematic configuration and measurement principle of the stage are described, and the vector transfer model is used to derive the compensated errors. The 6DFS is calibrated using a commercial laser interferometer and simple self-rotating table. Experimental results show that the residual error of the three miniature laser interferometers is ± 10 nm and the resolution of the angle measurement can reach 0.01 arc second within a measuring range of ± 30 arc seconds. The straightness error in the Z-direction is reduced from − 3 to 2 μm to ± 100 nm after compensating for the Bryan error. Contouring tests are performed to test the performance of the X–Y stage, and the results show that the positioning error is ± 10 nm in the X- and Y- directions. This paper presents a novel method to address the non-compensation of the Z-directional straightness error in the X–Y stages. The developed X–Y stage with a 6DFS can be used in nanofabrication and measurement machines in the semiconductor industry.