Monte Carlo simulations of magnetron sputtering particle transport

Monte Carlo simulations of the particle transport process during dc magnetron sputter deposition were performed to determine the energy and angular distributions of the energetic deposition species. The model itself is quite general, and here we present the specific example of hydrogenated amorphous silicon film growth. This process involves the sputtering of a silicon target in an argon-plus-hydrogen plasma. The three-dimensional model incorporates fractal trim data for the distribution of Si energies and emission angles sputtered from the target surface. Modified “universal” interatomic potentials are used to determine the scattering processes during gas phase transport. Energy and angular distributions of the deposition flux reaching the substrate are calculated as a function of pressure from 0.01 to 5.5 mTorr. As the pressure increases we find that the average energy per deposited atom remains essentially constant, but the energy and angular distributions of the arrival flux change dramatically.