Patent ID: 9068259
Filing Date: 2015-06-30
Classification: C23C,H01J,H02M

Abstract:
1. An AC power supply for a sputtering apparatus, the power supply comprising a DC electric power supply source and a bridge circuit made up of a plurality of switching elements connected between positive and negative DC outputs from the DC electric power supply source to supply bipolar pulsed electric power to two sputtering targets contacting a plasma at a predetermined frequency by switching each of the switching elements of the bridge circuit, wherein the AC power supply comprises: an inductor having a predetermined inductance value, the inductor being disposed in at least one of the positive and the negative DC outputs from the DC electric power supply source to the bridge circuit; and a snubber circuit in parallel with inputs to the bridge circuit, wherein the snubber circuit is disposed between the inductor and the bridge circuit, the snubber circuit having a diode and a capacitor connected in series with each other, the snubber circuit further having a resistor one end of which is in connection between the diode and the capacitor and an opposite end of which is in connection between the DC electric power supply source and the inductor.