Numerical Analysis of the Incident ion Energy and Angle Distribution in the DC Magnetron Sputtering for the Variation of Gas Pressure

Abstract

The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

Particle-in-Cell Simulations for the Improvement of the Target Erosion Uniformity by the Permanent Magnet Configuration of DC Magnetron Sputtering Systems

“…The fundamentals of this phenomenon are not fully analyzed here, but an additional electron heating mechanism exists in addition to the γ-mode in typical DC or DCMS plasmas, unlike the 500 G case. The striation of DCMS plasmas is barely found at pressures higher than a few mTorr, as shown in the previous study with a similar magnetic condition [20]. The striation phenomenon may have a sudden transition regime depending on the magnetic field intensity, which will be investigated more in future work.…”

“…Therefore, the magnetized electrons directly affect the ionization region and the spatial distribution of DCMS plasmas. DCMS plasmas were simulated with fluid approaches [7][8][9][10], kinetic approaches [11][12][13][14][15][16][17][18][19][20][21][22][23][24], or hybrid methods [6,7,[25][26][27][28][29]. However, the validity of fluid models is limited by gas pressure, which should be high enough to apply the fluid assumptions.…”