“…With the technological development of the semiconductor industry, manufacturers demand more precise performance from the wafer stage. To achieve the goal, researchers have developed many control strategies and applied them on the wafer stage, including iterative learning control (ILC) (Heertjes and Tso, 2007;Mishra and Tomizuka, 2009;Sun et al, 2014;Zheng et al, 2017), sliding mode control (SMC) (Heertjes and Verstappen, 2014;Li et al, 2016;WU et al, 2011;Ito et al, 2014), H∞ feedback control (van de Wal et al, 2002), multi-rate control (Sun and Tomizuka, 2016) and so on. Among them, SMC has attracted great attention for its simple implementation and robust performance in the presence of uncertainties and external disturbances (Fukushima et al, 2014;Kuang et al, 2019).…”