Inertial feedback control of a metrology frame in a lithography machine

Abstract

Lithography machines are used in the high precision production of microchips. Disturbance forces and floor vibrations can interfere with the imaging performance of the projection lens, which is mounted on a metrology frame and must be kept vibration-free. Therefore the metrology frame is dynamically isolated using pneumatic isolators. This paper proposes an inertial feedback controller for vibration isolation of the metrology frame. The main goal is to reduce the influence of floor vibrations and disturbance forces to the metrology frame. A smart sensor mixing strategy using position/acceleration control and known system information is structurally designed using H1 control. The control strategy is successfully tested and validated on an experimental setup.

Date of Award	31 Aug 2014
Original language	English
Supervisor	Hans Butler (Supervisor 1) & M. van Duijnhoven (External coach)