PRESSURE-DEPENDENCE OF IONIZATION EFFICIENCY IN SPUTTERING MAGNETRONS

Using a Monte Carlo simulation, we show how electron confinement allows sputtering magnetrons to operate at lower neutral pressures than similar unmagnetized devices. We find that at both high and low pressures, the ionization efficiency in a magnetron is constant, and it varies by only 40% between the two regimes. In contrast, the efficiency of an unmagnetized discharge varies linearly with pressure, becoming very small at low pressures.