Optimization Design Method of a 6-DOF Micromanipulation Mechanism for Extreme Ultraviolet Projection Lithography Objective Lens

Abstract

The six-degree-of-freedom (6-DOF) micromotion mechanism is a key component in extreme ultraviolet (EUV) projection lithography objectives to compensate for wavefront aberration and ensure performance stability. It is required to have high precision and high reliability. A 6-DOF mirror micromotion mechanism of an EUV lithography objective lens with Stewart configuration is proposed, and based on the RPY (Roll-Pitch-Yaw) angular rotation method and the second-type Lagrange method, the kinematic and dynamic models of the mechanism are constructed to realize the decoupling of the mechanism’s kinematics and the solution of the driving force. Comparative verification with finite element transient analysis shows that the response value of the dynamic model and the finite element method (FEM) differs by 4.8% in a specific posture. A hybrid optimization method, combining genetic algorithms and particle-swarm optimization (GA-PSO), was proposed to optimize the structural parameters of the initial design of the motion outriggers in a micromotion mechanism. The results demonstrate a 15.1% reduction in maximum driving force, significantly enhancing outrigger driving smoothness.