ASML and TU Delft are collaborating in the field of photo-acoustic subsurface atomic force microscopy (pass-AFM). In pass-AFM, the cantilever of an atomic force microscope is used as a GHz ultrasound transducer to create three-dimensional images of an object, in a similar way to medical ultrasound techniques. Due to the very high GHz frequencies and nanometer transducer size, this provides a unique, nanometer spatial resolution in three dimensions.
Before this collaboration, the principle was no more than an idea. The intensive collaboration has ensured that the most important bottlenecks for further utilization have been resolved. Within this renewed collaboration, we are dotting the i's and crossing the t's and we are going to understand where the most important challenges lie in terms of reproducibility of the measurements, something that is very critical for use in an industrial environment such as an ASML machine.