Spatially resolved ion energy distribution measurements in a large-area planar microwave plasma

Abstract

By employing a movable retarding field analyser, ion energy distribution (IED) functions have been measured in a large-area microwave plasma at pressure, ranging from 0.3 to 0.8 mbar which are typical for the use of this plasma source. It can be shown that the IED functions are fully developed with decreasing exponential shapes. For a given microwave power, the IED function extends towards higher energies with increasing pressure. The mean ion energy also increases with increasing pressure and decreases with increasing distance from the active plasma region. The relationships between microwave power and mean ion energy are complex, but it is clear that the influence of microwave power on the IED and mean ion energy decreases at lower pressures and larger distances from the active plasma region. The mean ion energy near the active plasma region decreases strongly with the distance from the centre of the microwave coupling window and this implicitly shows that the plasma possesses a strongly inhomogeneous internal field structure in this direction.

Ion damage effects from negative deflector plate voltages during the plasma-assisted molecular-beam epitaxy growth of dilute nitrides

“…16,17 They have the added benefit of being simple to construct. It was equipped with a similar pumping configuration as the MBE growth chamber involving cryo-and turbo-molecular pumps.…”

“…It was equipped with a similar pumping configuration as the MBE growth chamber involving cryo-and turbo-molecular pumps. The grid closest to the collector plate was biased at −20 V to return any secondary electrons back to the collector plate, 16 and the outer grid was grounded to decouple any electric fields from the plasma and/or deflector plates with that of the collector plate. This pressure is identical to that which was measured with the beam equivalent pressure gauge located on the backside of the substrate manipulator during growth of the samples in the MBE chamber.…”