Atomic scale smoothing of nanoscale quartz mold using amorphous carbon films

Abstract

Surface roughness control of the end products is increasingly becoming significant, especially with the miniaturization trends in the semiconductor industries. Ultra-thin amorphous carbon film offers a prime solution to optimize surface roughness due to its outstanding characteristics. In this study, hydrogenated amorphous carbon (a-C:H) films are deposited on two-dimensional quartz plates and three-dimensional quartz molds to evaluate the growth mechanisms and changes in the surface roughness, which is supported by molecular dynamics simulation. Results reveal that surface roughness encounters multiple variations until it reaches stable values. These fluctuations are categorized into four different stages which provide a concrete understanding of various growing mechanisms at each stage. Different behavior of the atoms in the top layers is recorded in the cases of normal and grazing incidents of carbon atoms. lower surface roughness values are obtained at low-angle deposition. Interestingly, surface smoothing is attained on the sidewalls of nanotrench mold where the deposition occurs with high incident ion angles.