Ultra-smooth surface preparation with gas cluster ion beams

The gas cluster ion beam (GCIB) realizes an ultra low-energy ion beam (of the order of several eV) and exhibits strong surface smoothing effects at normal incidence. One of the most significant differences of the GCIB smoothing process from other mechanical polishing techniques is that it can smooth a non-planar surface or a local area of the surface by controlling the beam steering. In this work, we introduce a state-of-the-art smoothing technology with the GCIB process, and apply it to the smoothing of widegap semiconductors (6H-SiC and GaN) and metal (Cu) substrates.