Characterization of an asymmetric parallel plate radio-frequency discharge using a retarding field energy analyzer

Gao

Journal of Applied Physics

et al. 2014

Radial uniformity measurements of plasma density were carried out by using a floating double probe in a cylindrical (21 cm in electrode diameter) capacitive discharge reactor driven over a wide range of frequencies (27–220 MHz). At low rf power, a multiple-node structure of standing wave effect was observed at 130 MHz. The secondary density peak caused by the standing wave effect became pronounced and shifts toward the axis as the driving frequency further to increase, indicative of a much more shortened standing-wave wavelength. With increasing rf power, the secondary density peak shift toward the radial edge, namely, the standing-wave wavelength was increased, in good qualitative agreement with the previous theory and simulation results. At higher pressures and high frequencies, the rf power was primarily deposited at the periphery of the electrode, due to the fact that the waves were strongly damped as they propagated from the discharge edge into the center.

Section: Experiments Setupmentioning

confidence: 99%

Experimental observation of standing wave effect in low-pressure very-high-frequency capacitive discharges

Gao

Journal of Applied Physics

et al. 2014

“…In this paper, we report the first measurements of energetic electrons in the downstream region of the CFDL in the Njord device, applying a Retarding Field Energy Analyzer (RFEA). By inverting the grids of an RFEA, the probe can be applied to measure the flux of the high-energy tail of electrons [23][24][25][26]. In Section 2, the experimental setup and diagnostics is explained, and the measured distributions of energetic electrons are reported and discussed in Section 3.…”

Section: Introductionmentioning

confidence: 99%

RFEA Measurements of High-Energy Electrons in a Helicon Plasma Device with Expanding Magnetic Field

Gulbrandsen

Fredriksen

2017

Front. Phys.

In the inductively coupled plasma of the Njord helicon device we have, for the same parameters as for which an ion beam exists, measured a downstream population of high-energy electrons emerging from the source. Separated measurements of energetic tail electrons was carried out by Retarding Field Energy Analyzer (RFEA) with a grounded entrance grid, operated in an electron collection mode. In a radial scan with the RFEA pointed toward the source, we found a significant population of high-energy electrons just inside the magnetic field line mapping to the edge of the source. A second peak in high-energy electrons density was observed in a radial position corresponding to the radius of the source. Also, throughout the main column a small contribution of high-energy electrons was observed. In a radial scan with a RFEA biased to collect ions a localized increase in the plasma ion density near the magnetic field line emerging from the plasma near the wall of the source was observed. This is interpreted as a signature of high-energy electrons ionizing the neutral gas. Also, a dip in the floating potential of a Langmuir probe is evident in this region where high-energy electrons is observed.

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

“…18,19 In Fig. In this article, several prototypes of the commercially available SEMION probe from Impedans, Ltd., were used.…”

Section: B Retarding Field Analyzermentioning

confidence: 99%

“…The second probe is a retarding field analyzer (RFA) 18,19 that gives information on the ion flux and the ion velocity distribution function (IVDF). The second probe is a retarding field analyzer (RFA) 18,19 that gives information on the ion flux and the ion velocity distribution function (IVDF).…”

Section: Introductionmentioning

confidence: 99%

Silicon etching in a pulsed HBr/O2 plasma. I. Ion flux and energy analysis

Haass

Darnon

Cunge

et al. 2015

The ion flux and ion velocity distribution function are studied using a capacitively coupled radio frequency ion flux probe and a multigrid retarding field analyzer in an HBr/O 2 pulsed plasma process, dedicated to silicon etching in gate or shallow trench isolation applications. A decrease of the duty cycle of the pulsed plasma etch process affects strongly these parameters: the mean ion flux decreases almost by the square of the duty cycle. Furthermore, the contribution of high energy ions from the on-time of the plasma is strongly reduced while their energy is slightly increased. In average, this leads to a significantly reduced ion energy and a reduced ion flux in the pulsed plasma compared to the continuous wave plasma.