Reliable characterization of materials and nanostructured systems <<50nm using coherent EUV beams

Coherent extreme ultraviolet beams from tabletop high harmonic generation offer revolutionary capabilities for observing nanoscale systems on their intrinsic length and time scales. By launching and monitoring acoustic waves in such systems, we fully characterize the mechanical properties of sub-50nm films. We find that the Poisson's ratio of low-k dielectric materials does not stay constant as often assumed, but increases when bond coordination is below a critical value. Within the same measurement, by following the heat dissipation dynamics from nano-gratings of width 20-1000nm and different periodicities, we confirm the effects of a newly identified collectively-diffusive regime, where closely-spaced nanowires cool faster than widely-spaced ones.