Nano-holes in silicon wafers using laser-induced surface plasmon polaritons.

Surface Plasmon Polaritons (SPPs) have been explored for a multitude of applications including sub-wavelength lithography, data storage, microscopy and photonics. In this paper, we report the use of SPPs for nanomachining silicon in massively parallel fashion. A Q-switched Nd:YAG laser beam was impinged on gold-thin film deposited, porous alumina membrane (PAM) that contains periodic 2-D array of thousands of nano-holes. The silicon substrate was placed in close proximity with PAM. The formation of SPPs and their coherent interference at the exit of PAM holes created strong nanoscale electrical fields which in turn produced 50-70 nm diameter holes in silicon.