Effect of Cluster Ion Bombardment on the Roughly Polished Surface of Single-Crystal Germanium Wafers

The surface treatment of single-crystal germanium with an argon cluster ion beam has been investigated. The original surface of the germanium wafers was bombarded with argon cluster ions with high (105 eV/atom) and low (10 eV/atom) specific energies. Using an atomic force microscope, images were obtained and a comparison of the surface topography before and after cluster ion bombardment was conducted. The smoothing of the surface was demonstrated using the power spectral density function of roughness in the range of spatial frequencies: 1) \(\nu=1{-}8\) \(\mu\)m\({}^{-1}\)—for the high-energy mode; 2) \(\nu=0.7{-}2.5\) \(\mu\)m\({}^{-1}\)—for the low-energy mode.