Monte Carlo simulation of the thermalization of sputtered atoms and reflected atoms in the magnetron sputtering discharge

Abstract

The Monte Carlo simulation code acat−gas has been developed in order to simulate the whole system of a planar magnetron sputtering discharge. The atomic collisions in the cathode, which lead to sputtering and reflection, are simulated by the acat routine of the acat−gas code; the thermalization of emitted atoms in the background gas within the a planar sputtering discharge is simulated by the Monte Carlo technique, where the Thomas–Fermi–Morse potential is used to describe collisions between ejected atoms and background gas atoms. The simulated average energy of sputtered atoms at the midpoint between the cathode and the substrate is in good agreement with experimental results. It is found that various physical quantities such as the velocity distributions of sputtered atoms and reflected atoms, the transmission rate of sputtered atoms and reflected atoms, the average energies in the background gas, and the normalized energy of arriving reflected atoms at the substrate depends strongly on the discharge voltage at the low pressure (<2 Pa).