Enhancing the performance of wafer scanners to power our digital world
Nic Dirkx defended his thesis at the department of Mechanical Engineering on October 6th. What is particularly interesting about this promotion is that Dirkx did this as part of his role at ASML being only 1 day a week at the university, and then in just 5 years. Through this he connected application and academic work.
The digital revolution is all around us, reshaping almost every facet of our everyday lives. Digital platforms and devices, as the internet and smartphones, have transformed the way that people interact, work, learn, and entertain. Innovations in digital technology have also enabled developments in renewable energy sources and healthcare, and are a determining factor for economic growth. The advancements are fueled by the continued development of more powerful and more affordable computer chips, or microchips. The results of this research form an important contribution towards creating the next-generation chip machines that will power our increasingly digital world.
Vital to the development of the microchips is the process of miniaturization, referring to the trend of fitting ever more and ever smaller electrical components into a chip. This trend, as already described in the sixties by the famous Moore's Law, has not ceased to apply to this day. As a result of decades of miniaturization, today’s microchips consist of nanoscale patterns and structures that can only be seen through specialized microscopes.
More extreme levels of precision
Most of the high-end microchips that are found in the world are produced by chip machines that are built by ASML in Veldhoven, the Netherlands. These chip machines, called wafer scanners, form the highly sophisticated machines that are responsible for the most difficult step in the chipmaking process: the lithography step. In this step, the pattern of the chip is laser-imprinted onto a substrate, called the wafer. To sustain the quest for ever more miniature microchips, the next generation wafer scanners are demanded to perform at ever more extreme levels of precision, pushing the boundaries of science, engineering, and technology.
Improved modeling and control techniques
The pursuit of improved precision poses significant challenges for the design of the control systems that are responsible for the accurate positioning of the many machine components. In turn, these control systems rely on the availability of mathematical models that describe the dynamic behavior of these components in great detail.
This study is aimed at enhancing the performance of wafer scanners via the development of new and improved modeling and control techniques. These methods together cover the full design process from experiment to measured data, from data to models, and from models to control design. By effectively dealing with the envisaged complexities of future wafer scanners, the methods developed in this study enable chip machines to reach new levels of precision.
Title of PhD thesis: Wafer Stage Motion Control from Experiment Design to Robust Performance. Supervisors: Tom Oomen and Koen Tiels.