AVS 58th Annual International Symposium and Exhibition
    Thin Film Division Thursday Sessions
       Session TF2-ThM

Paper TF2-ThM1
Aluminum Molecular Model for DSMC Simulations of Thin Film Deposition

Thursday, November 3, 2011, 8:00 am, Room 110

Session: Modeling and Analysis of Thin Films
Presenter: Alina Alexeenko, Purdue University
Authors: A. Venkattraman, Purdue University
A. Alexeenko, Purdue University
Correspondent: Click to Email
The direct simulation Monte Carlo (DSMC) technique has been shown to be able to predict various properties of thin films grown using vacuum deposition methods such as CVD, PVD, EBPVD. Such simulations can also provide information about the energy distribution and orientation of vapor molecules striking the substrate which are critical inputs to the prediction of the grain size, residual stress and other properties of the deposited films. One of the most important inputs to a DSMC simulation is the molecular model that determines the interaction between the simulated particles. The variable hard sphere (VHS) model that is widely used due to its combination of simplicity and accuracy is typically determined by fitting to viscosity data obtained from experiments. In the absence of direct measurements of transport coefficients for metal vapors such as Aluminum, one needs to resort to other techniques to determine a set of accurate molecular model parameters. In this work, we compare DSMC simulations with Aluminum thin film deposition experiments to determine the VHS model parameters. The growth rate of the thin films at the substrate location depends strongly on the transport properties of the metal vapor – viscosity being one of the most important – and hence can be compared with the DSMC simulations to determine a suitable molecular model. In a similar analysis for copper published earlier, we used experimental data available in literature while the experiments for this study are performed in the electron-beam evaporator in the Birck Nanotechnology Center at Purdue University.