The PIC/MC Simulation Of Magnetized Capacitively Coupled Plasma

Plasma plays a crucial role in very large scale integrated circuit manufacturing device. As is equipped with various advantages, such as high plasma density and high rate of deposition, magnetized plasma sputtering is widely used in film deposition process, which arouses great interests among researchers all over the world.During the process of magnetized discharge, different parameter combinations play different roles on the target’s use ratio and plasma characters. In this work, a2d3v(two dimensions in coordinate, three dimensions in velocity) PIC/MC(Particle-In-Cell/Monte Carlo, PIC/MC) simulation method coupled with external circuit model self-consistently is applied to study the influences of external circuit, magnetic field and geometric effect on argon CCP(Capcitively Coupled Plasma, CCP) in a dc(direct current, dc)/rf(radio-frequency, rf) magnetron. The results demonstrate that the external circuit resistance is a key factor to maintain the discharge stability in a dc magnetron. With the increase of the external circuit resistance, the plasma density becomes low and the dc bias on the cathode turns small. The flux of Ar+arriving at the cathode and Cu sputtering from the target decrease resulting from the increasing external circuit resistance, while the sputtering yield still keeps constant. The ion energy distribution consists of two parts, i.e. a peak in low energy zone and a tail in high energy zone, resulting from the nonuniform of the plasma density in axial direction.Regarding the study of argon CCP in a rf magnetron, the results show that the magnetic field enhances plasma’s locality. With the increase of magnetic strength, the plasma density first turns high then becomes low, whose peak shifts from the region near powered electrode to the region close to grounded electrode. The electric field in the sheath of powered electrode first becomes strong then turns weak, while the one in the sheath of ground electrode is still becoming stronger, both in axial direction and radial direction. When the amplitude of magnetic field is changed, the main heating zone of electron varies. Besides, the dc self-bias first increases, whose value changes from negative one to positive one, then keeps constant, at last increases again. The ion energy distribution shifts to the low energy zone due to the decreasing potential drop in sheath. With the increase of the gap between powered electrode and grounded electrode, the plasma density turns low, the peak of which shifts from the region near powered electrode to the region close to grounded electrode. What’s more, the electric field and potential drop in the sheath of powered electrode keeps unchanged while the electric field in the sheath close to grounded electrode increases. Finally, dc self-bias and plasma potential ascend.