Common zeros in synchronization of high-precision stage systems

Abstract

In synchronization of high-precision motion systems, in particular the synchronization between a wafer stage system and a reticle stage system of a wafer scanner, a novel feedforward structure is studied. In this structure, the numerator of each plant model is described by an input shaping filter capturing the zeros of said model. The denominator is described by a feedforward filter capturing the poles. Ideally, this gives zero error tracking of both the reticle and wafer stage systems without the need for plant inversion. But in view of the different input shaping filter operations, appropriate synchronization behavior is not guaranteed. To obtain both appropriate tracking and synchronization behavior, we propose to augment the reticle stage filters with the zeros from the wafer stage plant model. Reversely, the wafer stage filters are augmented with the zeros from the reticle stage plant model. The feasibility of such an approach is confirmed by simulation results and, to some extend, by measurement results obtained from an industrial wafer scanner.

On characterization of a generic lithography machine in a multi-directional space

“…Several studies contribute to enhance the lithography process. Some of these contributions are focused on the control aspect of the machine, as in [1,[9][10][11][12][13], and others are focused on introducing novel devices (or mechanisms) to improve the performance of this machine, as in [14][15][16].…”

Beyond decentralized wafer/reticle stage control design: A double-Youla approach for enhancing synchronized motion

“…The potential and industrial acceptance of add-on controller extensions has been confirmed in several preliminary ad hoc experimental studies. Research examples of improved synchronization by advanced feedforward can be found in Navarrete, Heertjes, and Schmidt (2015), see also Boeren, Bruijnen, van Dijk, and Oomen (2014) for related feedforward results. In Barton and Alleyne (2007) and Mishra, Yeh, and Tomizuka (2008) improved synchronization is achieved by using iterative learning control.…”

“…The present paper extends this to a more general setting containing more detailed proofs and explanation, and, in addition, C3, C4. Research related to results presented here includes Barton and Alleyne (2007), Temizer (2012), Lambregts, Heertjes, andvan der Veek (2015), Navarrete et al (2015) and Sakata and Fujimoto (2009). The framework guarantees robust stability under uncertainty in the system dynamics, finite accuracy of the plant model and neglected subsystem interaction components.…”