Numerical simulation of the discharge in d.c. magnetron sputtering

Numerical simulation of d.c. magnetron discharge for sputtering in Ar is performed using a hybrid model consisting of a particle model and a fluid model. The various discharges with different anode's size are simulated to investigate the effect of film conductivity on the anode and the substrate. In the case of a large area anode formed by the deposition of conductive material, the plasma potential becomes higher, suppressing the excess electron flux to the large anode. In the case of a small anode formed by an non-conductive film deposition, the plasma potential becomes lower, dragging a large number of electrons into the small anode. The low plasma potential lowers the potential difference between the cathode and plasma, and the production rate of an electron-ion pair decreases in the cathode sheath region under a constantly applied voltage mode, therefore decreasing the plasma density. It is shown that the plasma potential and the density changes with film conductivity or anode size under a constantly applied voltage. High energy ion injection to the central part of the glass substrate is estimated at the beginning of the film deposition. This implies that the film property at the central part of the non-conductive substrate will differ from the one at the other position due to the difference of the ion impact to the substrate.