Characterization of the resonant electromagnetic mode in helicon discharges

Low-field helicon discharges

Operation of helicon discharges at magnetic fields B0 below 100 G is of interest for plasma etching and deposition reactors if high ion flux can be maintained with reduced field requirements. The theory of coupled helicon and Trivelpiece–Gould modes is summarized for uniform B0. Initial results from two experiments are reported. The first has a single 5 cm diameter tube with B0 = 0–100 G inject...

Density jump in helicon discharges

Helicon discharges characteristically exhibit a sharp jump from low to high density as the radiofrequency (RF) power is raised. This is usually explained by the transition from an inductively coupled plasma (ICP) mode to a helicon mode when the dispersion relation for helicon wave propagation is satisfied at a critical power or magnetic field. Experiments have suggested a different mechanism fo...

Investigation of Electromagnetic Field Penetration in ICP, Weakly-Magnetized ICP and Low-B Helicon Discharges

Helicon discharges and sources: a review∗

Helicon waves are waves in low-temperature, partially ionized plasmas in a dc magnetic field (B-field). The study of helicons involves both ion–neutral collisions and Larmor orbits, even when the B-field is uniform. Helicon discharges are ionized by helicon waves generated by a radiofrequency (RF) antenna. Interest in helicon discharges arose because of the high plasma densities they generate c...

REVIEW ARTICLES Physics of helicon discharges*

Because of their high density, low-pressure discharges ionized by helicon waves are being studied for their possible use in cluster tools for the fabrication of next-generation computer chips. How helicon waves are related to whistler waves and waves in a plasma-filled waveguide is explained, and the mystery of the high ionization efficiency is outlined. Experimental data on the waves and the e...