A planar-type surface-wave plasma source with a subwavelength diffraction grating inclusion for large-area plasma applications

Abstract

The electromagnetic wave through the subwavelength diffraction grating can be largely absorbed by surface-wave plasmas (SWPs). A SWP source is built with two slot-array antennas element. Due to the dissipation of surface waves in overdense plasmas, this source can provide remarkable discharge efficiency of 4.4 cm2/W experimentally and 96% of incident power numerically. When the applied power as low as 200 W is supplied to the SWP source, a homogeneous plasma with the uniform area up to 14×36 cm2 and the plasma density up to 1.04×1018 m−3 is generated under the quartz slab. By varying the incident power and gas pressure, the parameter of plasmas can be easily controlled without density jumping. Moreover, the characters of bi-Maxwellian electron energy distribution prove that our SWP source yield plasmas by surface heating actually. These excellent performances make the proposed source meet the requirements in large-area plasma processing and also give its advices for plasmas heating in next meter-size SWP sources.