Computer Simulation Of The Transportation And The Sputtering Of Ions In RF Magnetron Sputtering

RF (radio frequency) magnetron sputtering that has been broadly used to fabricate varieties of thin films is a kind of physical vapor deposition (PVD). A majority of studies has to date been focused on studying the influence of fabricating conditions on the characteristics of thin films and finding the ideal conditions to fabricate the thin films with favorite characteristics via experiments which are expensive and time-consuming.Computer simulation that is now becoming a more and more important method for scientific research and can be used as a complementary to theory and experiment has been employed to research the growth of thin films.The main purpose of this article is to simulate the whole process of the generation and transportation of ions in RF glow discharge, sputtering of target and transportation of sputtered atoms, via MC models that are established on the basis of the physics of sheath theory for the RF magnetron glow discharge,sputtering theory and transportation theory. The software "SFD"is employed to simulate the processes of whole work.The different processes can be simulated separately or sequentially with the results of the simulation of the former process as the inputs of the simulation of the closely following process.The energy, directions and the positions of the particles, as well as the distribution of ions' angle and energy in the different distance of the cathode sheath are concerned in this article. The main results are listed below:(1) The software SFD was designed to silmulate the transportation of ions in sheath of plasma of the RF magnetron sputtering, in which a simple method to determine the original states of the ions (original velocities and positions) is recommended.(2) The phenomena of ion acts on target was simulated by softeware SRIM 2003, including the different angle, energy, and position, and get the relation of them.i) Energies of the incident ions to the target are determined mainly by the voltage across the cathode sheath, with a majority of ions' energy vary around thesheath voltage; influenced by magnetron field some ions has low energy, others, rates of ions with high energy down with the rise of pressure.ii) Energies of the sputtered atoms vary mainly from several to several teens eV, with few atoms' energy relatively high; the emitting positions of the sputtered atoms are close to the corresponding incident ions (in the order of angstrom); the sputtered atoms are emitted mainly normally, and few are slantways; energy and angular distributions of sputtered atoms are influenced by the energies and incident directions of incident ions, but the angular distributions are not influenced by the incident energy very greatly.iii) The contributions of the pressure were contradictory, in one hand, it rise the speed of sputtering by rising the density of plasma, in the other hand, it reduce the speed by the rates' rising of collision.iv) Transportation properties of the sputtered atoms are mainly influenced by the air pressure P in the vacuum chamber and the distance from the target to substrate, that is to say, the bigger the product P X d, the fewer the sputtered atoms reaching the substrate; Energies of the sputtered atoms reaching the substrate are mainly around several eV, with a peak in the very low energy that results from the collision and thermalization; the distribution of the sputtered atoms on the substrate plate after they arrive there extents radially, and uniformly, but mainly confined above the target.(3) The simulation results of rare gas ion (argon is used here) sputtering metal (Cu is used here) to deposit films, which are in good agreement with the fundamental experimental results.