Large area VHF plasma sources

Array antenna, a novel plasma source, was developed to realize uniform deposition of silicon thin films such as amorphous silicon and microcrystalline silicon on large area substrates with power frequency in the VHF band. It consists of plural U-shaped loop antenna type electrodes, and silicon thin films are uniformly deposited on over > 1 m2 substrates by introducing VHF power at 85 MHz with anti-phase. The VHF PCVD system with array antenna is suitable for the mass-production of silicon thin film solar cells due to its high throughput achieved by double-sided, multi-zone deposition.