Design of pulsed DC magnetron sputtering power supply with adjustable igniting voltage

Plasma sputtering technology is widely used in high-end manufacturing industries, such as material surface treatment. Pulsed DC plasma sputtering technology is preferred over continuous DC power supplies due to its greater process control flexibility and improved energy utilization efficiency. The sputtering power supply operates in a pulse mode, where the main challenge to ensure rapid ignition of each pulse and maintain a constant root-mean-square (RMS) pulse current. This paper proposes a novel pulsed DC sputtering power supply topology. By utilizing the dead time of the full bridge converter and the control sequence of the pulse generator, a pulsed output is achieved. This approach significantly reduces the current and voltage stress limit on the switching devices within the pulse generator. Furthermore, the pulse generation circuit is designed to achieve fast and stable pulse current, with an adjustable and controllable ignition voltage at the leading edge of the pulse. A 20 kW prototype was developed to validate the design. The output repetition frequency reaches up to 100 kHz, the duty cycle is adjustable between 10 % and 100 %, and the maximum ignition voltage reaches 2 kV, making it suitable for a wide range of sputtering load requirements.