Estimation of the pressure-distance product for thermalization in sputtering for some selected metal atoms by Monte Carlo simulation

We propose a method to obtain the pressure-distance product (pd) for thermalization in the sputtering process using a Monte Carlo (MC) simulation. Sputter-ejected atoms proceed forward with high energy, and fall into random motion finally. That is, after many MC trials the "average position" of atoms reaches saturation. The thermalization distance d can be estimated from this saturation position. We could obtain the pd product for Al, Cu, and Mo in argon atmosphere. The pd values agreed well with the pressure dependence of the deposition profile observed experimentally. (C) 2014 The Japan Society of Applied Physics