Broad ion energy distributions in helicon wave-coupled helium plasma

Abstract

Helium ion energy distributions were measured in helicon wave-coupled plasmas of the dynamics of ion implantation and sputtering of surface experiment using a retarding field energy analyzer. The shape of the energy distribution is a double-peak, characteristic of radiofrequency plasma potential modulation. The broad distribution is located within a radius of 0.8 cm, while the quartz tube of the plasma source has an inner radius of 2.2 cm. The ion energy distribution rapidly changes from a double-peak to a single peak in the radius range of 0.7–0.9 cm. The average ion energy is approximately uniform across the plasma column including the double-peak and single peak regions. The widths of the broad distribution, ΔE, in the wave-coupled mode are large compared to the time-averaged ion energy, ⟨E⟩. On the axis (r = 0), ΔE/⟨E⟩ ≲ 3.4, and at a radius near the edge of the plasma column (r = 2.2 cm), ΔE/⟨E⟩ ∼ 1.2. The discharge parameter space is scanned to investigate the effects of the magnetic field, input power, and chamber fill pressure on the wave-coupled mode that exhibits the sharp radial variation in the ion energy distribution.

Effects of power on ion behaviors in radio-frequency magnetron sputtering of indium tin oxide (ITO)

“…Therefore, a thorough examination of the IEDFs for common ions, such as Ar + , In + , O + , O − , , and InO − , has been carried out. The IEDFs for Ar + and In + ions display a distinct doublepeak structures, which are commonly observed in radiofrequency discharges [22][23][24]. In these studies, IEDFs are measured using retarding field energy analyzers with scanning biased grids.…”

Autonomous, Additively Manufactured, Multi-Langmuir Probe for CubeSat Plasma Diagnostics

“…For example, helicon plasmas are created by applying an RF signal to a gas, causing the gas to ionize and become a plasma. The number density of the plasma, 𝑛, will increase with the RF power [16]. Similarly, the electron temperature, 𝑇 #$ , will increase slightly with RF power, but to a much lesser degree than 𝑛 [18].…”

“…()+% , respectively). The electron temperature (in eV), 𝑇 #$ , is found from the linear fits of all three regions via [16] Fig. 1.…”

Crystallographic analysis of nano-tendril bundle vs fuzz growth on tungsten exposed to helicon wave-coupled helium plasma

“…The different characteristic modes of the 13.56 MHz RF plasma source affect the ion energy distribution incident on the samples. 29 In the inductively coupled mode, the plasma potential is approximately uniform. A sample that is placed in this plasma experiences an ion flux that has a narrow ion energy distribution, subjecting the sample to constant ion energy to within ±4 eV.…”