Prof. Hans Butler
Mechatronic challenges in optical lithography
In lithographic tools used in chip manufacturing, the imaging resolution (capability to create small features) is physically limited by the optics and the light source wavelength. In the course of time, many solutions have been pursued to push this resolution to smaller values, with significant consequences for the mechatronic designs in the machine. In immersion systems, a layer of water is contained between the projection lens and the wafer. Multiple patterning techniques create a dependency of (layer-to-layer) overlay errors with imaging performance, creating tight requirements on stage accuracy. Extreme-ultraviolet lithographic tools have to operate in vacuum, and next-generation, high-NA EUV tools will use anamorphic optics.
This talk introduces the latest solutions for making smaller features already in operation today, and also looks ahead to future systems. The mechatronic challenges and solutions associated with these techniques will be addressed.
Hans Butler obtained his M.Sc. and Ph.D. degrees in adaptive control at Delft University of Technology in 1986 and 1990, respectively. After joining ASML in 1991, he has developed controllers for multiple high-precision modules in lithographic tools such as handlers, illuminators, projection systems, and stages. He has led groups working on actuators, opto-mechatronics, and system dynamics. Since 2010 he is an ASML fellow with dynamics and control as his main focus area. Since 2012 he is a part-time full professor at the Control Systems group of the Electrical Engineering Faculty at the Eindhoven University of Technology, with a main focus on high-accuracy mechatronic systems.