Large-diameter high-density plasmas such as electron-cyclotron-resonance (ECR), helicon wave, inductively coupled, and surface-wave plasmas are currently being developed for plasma-assisted thin-film processes in the next generation. Actual applications of such high-density plasmas require a deeper understanding of discharge physics as well as advanced techniques for plasma control. In this paper, new findings on antenna - plasma couplings are reported. One is resonant directional excitation of helicon waves and a mechanism of density jump in a helicon RF discharge. The other is the identification of long-wavelength surface-wave modes with observation of the short-wavelength mode in a planar microwave discharge. In addition, comprehensive diagnostics of a pulsed inductively coupled plasma in chlorine is presented, which explains the pronounced effect of pulsed power discharges on charge-up suppression.
Helicon wave coupling in KSTAR plasmas for off-axis current drive in high electron pressure plasmas