Selfconsistent simulation of sputter deposition with the Monte Carlo method

Low pressure sputter atom deposition is a commonly used method for coating and trench filling in semiconductor chip manufacturing. In this paper we present a selfconsistent simulation of this process in which both the sputtered atoms and the background gas are computed by means of the Direct Simulation Monte Carlo (DSMC) method. The results allow a detailed exploration of the sputtering wind effect and indicate that sputter atoms approach equilibrium more slowly than previous test particle Monte Carlo simulations have found. A new molecular collision scatter law for DSMC is introduced that simulates particle interactions more accurately with no additional computational cost. Its use for general DSMC calculations is recommended.