Keynote presentations
Keynote1
Wim Symens, ASML.
Dynamics & Mechatronics in Lithography
In the semiconductor industry, steppers and scanners are used to manufacture integrated circuits (ICs) via a lithographic process. These highly complex devices use an optical system to print an image of a pattern on a quartz plate, called the reticle, onto a photosensitive layer on a substrate, called the wafer. The circular wafer can contain many ICs, typically 100 or more, and needs to be repositioned from exposure to exposure of each IC. Moreover, different patterns need to be put exactly on top of one another, even when the wafer has left and re-entered the machine to accommodate for intermediate process steps. To be able to pack more functionality into each IC and to increase the productivity of the machine, the required accuracy and speed for the repositioning is increasing as well. This poses ever more stringent dynamics and motion control challenges to lithographic steppers and scanners.
In this presentation, the lithographic process will be explained and the dynamics, motion control as well as the metrology architecture of ASML's scanners will be detailed. It will furthermore be shown which evolutions were necessary to keep up with the ever increasing demands for shrink and increasing throughput.
Keynote2
Matthew Brake, Rice University.
The Dynamics of Jointed Structures: State of the Art and Perspectives for the Next Decade
Both experiments and physics-based modeling have elucidated that the features in a jointed interface can have an unexpectedly large influence on the nonlinear dynamics of a large-scale, assembled structure. Features internal to a jointed interface, which include the meso-scale topography and the sub-micron scale asperities, are often many orders of magnitude smaller in scale than the structure itself; however, despite this, these small-scale features govern the total contact stiffness, manifestation of friction and wear, and global dynamics of the structure. As such, not accounting for these features can lead to either premature failures due to wear/fatigue or significant reductions in efficiency for engines that are overdesigned. In order to make meaningful predictions of an assembled structure's dynamics (and thus wear/fatigue behavior or noise and ride characteristics), an open question is how to balance both deterministic, physics-based models of interfaces with statistical, uncertainty-based characterizations of features (such as distributions of asperities) that cannot be known without first building and measuring all parts of an assembly. Much of the recent research in jointed structures has focused on discovering the physics that govern the interfacial behavior, developing new experimental techniques to characterize a system's response more accurately, and numerical techniques to simulate the system's dynamics more efficiently. Despite the many recent advances, there are many challenges that still remain before accurate predictions of a jointed structure's nonlinear dynamics and wear properties become accessible to design engineers. Stemming from the conclusions of a recent international workshop on joint mechanics, this talk makes several recommendations for new research thrusts to improve the understanding of jointed structures in addition to highlighting the current state of the art and recent advances in modeling and experimentally characterizing jointed structures.