Novel high-frequency energy-efficient pulsed-dc generator for capacitively coupled plasma discharge

Area of Science:

• Plasma Physics
• Electrical Engineering
• Materials Science

Background:

• Capacitively coupled plasma (CCP) discharges require precise high-voltage pulsed DC power.
• Generating sharp, rectangular pulses with fast edges for capacitive loads is challenging due to high current demands.
• Existing systems often face limitations in pulse operation frequency.

Purpose of the Study:

• To design, assemble, and test a new high-frequency, high-voltage pulsed DC generator (PDG).
• To achieve almost rectangular high-voltage pulses with fast rising and falling edges for CCP discharge.
• To ensure stable plasma current control during pulsed operation.

Main Methods:

• Development of a PDG utilizing half-resonant converters and a constant current-controller circuit.
• Integration of high-voltage solid-state power switches for pulse generation.
• Modulation from a high-voltage DC input to a pulsed DC output, controlled by input signals and current levels.

Main Results:

• The PDG successfully generated pulses with rise/fall times <500 ns / <800 ns and minimum width of 1 µs.
• Achieved a maximum negative pulse voltage of 1000 V and a maximum repetition frequency of 500 kHz.
• Demonstrated stable plasma discharge current control and 85% energy efficiency at 1 kHz repetition rate.

Conclusions:

• The developed PDG effectively produces high-quality pulses suitable for CCP discharge.
• The half-resonant converters enable efficient energy recovery from capacitive loads.
• The PDG offers a more efficient solution for plasma processing applications using CCP.