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GaN luminescence, induced by ultraviolet light under/after inductively coupled plasma exposure, has been measuredin situandex situ. After the plasma exposure, both near-band edge (NBE) and yellow luminescence (YL) intensities decrease. The decay times of NBE and YL in thein situmeasurement are shorter than those of theex situmeasurement on account of the temperature rise induced by the plasma. On the other hand, with increasing plasma power, the decay times decrease. It is considered that this decrease is strongly related to non-radiative defects introduced by the Ar plasma. The results suggest thatin situphotoluminescence monitoring can be used to reveal plasma-induced damage at GaN surfaces. [ABSTRACT FROM PUBLISHER]

This work focuses on an improved method that enables us to measurein situGaN film photoluminescence (PL) under Ar or N2plasma etching. Although the background signal is large and increases with bias voltage, the GaN PL can be obtained after subtraction of this background from the total luminescence. Moreover, after plasma etching, the intensities of the near-band-edge and the yellow luminescence decrease significantly. It is suggested that this behaviour is strongly related to the heavy plasma-induced damage, which includes non-radiative defects and deep-level defects, such as Ga vacancies and/or C impurities. [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]