Search

The photoluminescence of n-type GaN thin films in an argon plasma condition has been studied byin situmeasurement. The characteristic near-band-edge (NBE) peak and yellow luminescence (YL) of GaN films are observed in the spectra. However, compared to the luminescence of GaN in air and in a vacuum, in the plasma of 80 W power, the NBE peak and YL intensity first increase dramatically and then decrease with extended time. The effects are attributed mainly to an increasing temperature induced by the plasma, but also to a lesser extent by damage to the film caused by the plasma. [ABSTRACT FROM PUBLISHER]

This paper describes in-process measurements of secondary electron emission coefficient (SEEC) during plasma immersion ion implantation for a plane target. In the plane target, trajectories of secondary electrons (SEs) emitted from the target strongly depend on the plasma conditions as well as the amplitude of pulse voltages applied to the target because of variation of the curvature radius of the sheath formed around the target. Therefore, absolute measurements of the SE current as well as of the SEEC were difficult to perform. However, calibration of an SE detector using a plane target with very high SEEC enabled the SEEC measurements. The measurements of the SE current revealed that the sheath curvature was affected by the plasma condition and the target shape. This calibration will be useful for SEEC measurements of arbitrary-shaped target. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(3): 1–7, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20096 [ABSTRACT FROM AUTHOR]

This paper describes effects of vacuum ultraviolet (VUV) optical emission from the plasma on the secondary electron emission coefficient (SEEC) in PIII processes. To examine this, time-resolved measurements of the VUV emission intensity and the SEEC are performed in continuous and square-wave-modulated discharges. For all the measured data, a good linearity between the SEEC and the VUV intensity is found out, and the ion-induced SEEC can be distinguished from the photon-induced SEEC. In the afterglow of the modulated discharge, the SEEC decreases because the VUV emission intensity. Therefore, ion implantation in the afterglow allows us to reduce a current requirement of the pulse generator, leading to low-cost PIII processes. [Copyright &y& Elsevier]

Abstract: This paper reports on plasma parameters and ion composition of droplet-free Zr ion source for plasma immersion ion implantation and deposition (PIII&D). Zirconium (Zr) ions were obtained by ionizing sputtered Zr atoms in inductively-coupled argon discharge. The characteristics of plasma density, plasma potential and electron temperature were typical ones of such a inductive discharge, and the plasma parameters were not significantly influenced by mixing the sputtered Zr atoms into the plasma. Actually, the main ionic component was still Ar+ ions, and the ion density ratio of [Zr+]/[Ar+] was as low as ∼8%. Increase in sputtering rate of the Zr source will be necessary to improve the ion density ratio. [Copyright &y& Elsevier]