A scaled particle model of a DC sputtering magnetron

Summary form only given. A scaled two-dimensional particle-in-cell model of a planar DC sputtering magnetron is developed using the XOOPIC code1. The PIC model includes collisions through a Monte Carlo model, and includes the ability to calculate spatial, energy, and angular distribution functions for ions impacting arbitrary surfaces. Due to the large computational expense as well as a physical instability manifesting as asymmetry in the planar discharge associated with the non-reentrant configuration, a half plane model is developed to enforce symmetry. The instability does not exist in cylindrical configurations in which the ExB rotation of the plasma tends to maintain symmetry. The discharge was studied in argon from 5-20 mTorr, with driving currents from 150-600 mA for a 1.6 cm system (assumed 1 m in the ignorable direction). The results compare well with published experimental data2 though the model is run at O.lx physical size to reduce computation time. Narrow peaks in the spatial impact distribution of ions at the target correspond well to erosion tracks observed experimentally. Broad ion energy distributions (IEDs) are obtained at the target for the scaled model, narrowing as the dimensions, pressure, and current are increased. The angular distribution remains narrow, with a peak between 5-10 degrees from the normal. As the models are scaled up, the voltage in the current driven cases does not increase much, and the electron mean energy also remains nearly constant. Future work includes coupling the PIC model to include sputtering at the metal target as well as collisional transport of the sputtered metal flux to the substrate.