Professor Steve Franklin

Steve's research interests focus broadly on industrial applications of tribology. His current research centres on understanding and influencing friction and wear, including tribochemical wear, at different length scales down to the atomic level: which parameters affect the tribological behaviour over time and why, how can we influence it to improve high-precision positioning? These questions are of direct relevance to positioning challenges in nanolithography. Surface topography, surface coatings and controlled environments play important roles in finding ways to manipulate the tribological behaviour.

In ASML lithography machines, silicon wafers are loaded onto the wafer stage and subsequently moved in a horizontal direction with extremely high precision and acceleration. Variations in the friction between the wafer and the wafer stage lead to unpredictable positional errors during the lithography process and effectively limit the minimum achievable size of features on the chips. In the past, Steve has also carried out much research on the tribology of human tissue including skin, eyes and blood vessels, and on understanding the tribology of various materials such as hard coatings and polymers, all in order to enable the industrial development of improved products.