A 13.56-MHz ZVS Inverter for Radio-Frequency Capacitively Coupled Plasma Power Supply

Plasma power supply is an important equipment to output an adjustable radio-frequency voltage for generating capacitively coupled plasma (CCP). Nowadays, radio-frequency power amplifier (RFPA) is popular for implementing plasma power supply. However, a bulky matching network is needed to be located between the RFPA and CCP, resulting in low power density and high system complexity. In this article, a buck-type inverter is proposed to directly power CCP, which not only outputs an RF ac voltage with low harmonics, but also realizes zero-voltage-switching for power switch over a wide capacitive load range. The derivation of the buck-type inverter is presented, and a step-by-step parameters design approach is proposed. Finally, a 13.56-MHz, 28-W prototypeis fabricated and a CCP discharge experiment is carried out. The experimental results are provided to verify the effectiveness of the proposed buck-type inverter and parameters design approach. The power density of prototype is 15 W/in
³
, which is much higher than traditional plasma power supply with 0.06 W/in
³
.