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We have developed a technique for measuring the thickness of a deposited film and electron density simultaneously during plasma processing with two different-sized curling probes. The technique requires only two things; the measurement of resonant-frequency shifts occurring on the two probes before and after the processing, and the substitution of the frequencies into a set of two quadratic equations. The solutions of the equations lead to a simulated measurement of electron density and the thickness of films deposited on the probe surface. We placed a piece of polyimide tape on the probe surface to simulate the deposited film, and then exposed the probes to an argon plasma. In this report, we derived the thickness and pre-calibrated electron density simultaneously from the frequency shifts due to the film thickness and the plasma density. Our measurement showed the film thickness with 9% accuracy and the electron density in the order of 109 cm−3. This result revealed that the proposed technique is principally available for plasma processing. [ABSTRACT FROM AUTHOR]

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]

We have investigated in-situ photoluminescence properties of GaN surfaces exposed to Ar plasma. With increasing plasma exposure time, both intensities of near-band-edge (NBE) peak and yellow band luminescence (YL) significantly decrease, whereas that of blue band luminescence (BL) is seen to gradually increase. Additionally, the YL/NBE intensity ratio is almost invariant, but the BL/NBE intensity ratio increases dramatically with increasing the plasma exposure time. The results suggest that the increase in the BL intensity is probably due to the plasma-induced damage accumulation and the in-situ monitoring of the BL/NBE intensity ratio can be used to observe the plasma-induced damage. [ABSTRACT FROM AUTHOR]

The dispersion of multi-walled carbon nanotube (MWCNTs) in tetrahydrofuran (THF) will be compared for three different functionalizations with dielectric barrier discharge in this journal article. We found that the functionalization with the plasma discharge created with the mixture gas, argon(Ar)/nitrogen(N 2 )/hydrogen(H 2 ), was the most effective in dispersing MWCNTs in THF than the plasma created with the other two mixture gases, argon/oxygen(O 2 ) or argon/nitrogen. According to the gas composition creating the discharge, the amino group possibly affects the better CNT dispersion in THF. Our measurements with light transmission indicated that the MWCNTs functionalized with Ar/N 2 /H 2 plasma dispersed as much as 42.2 mg/L. [ABSTRACT FROM AUTHOR]