Effects of proton irradiations on GaN-based materials

We present the effects of proton irradiations on n-GaN and InGaN/GaN light emitting diodes (LEDs) investigated by secondary ion mass spectrometry (SIMS), circular transmission line model (CTLM), Raman and photoluminescence (PL) measurements. The SIMS results show that the depth of proton implantation is nearly proportional to the energy of the hot protons. Proton implantation can result in the quenching in the luminescence and the degradation in the conductivity of n-GaN, which were found to be preserved to the temperature for device processing of 750 degreesC. It was found that the intermixing of quantum wells (QWs) induced by proton radiations is negligible, and it is interesting to point out that InGaN/GaN QWs are more resistant to proton irradiations compared with the conventional III-V semiconductor QWs. Our results demonstrate the application of proton irradiations to the technology of electrical and optical isolation for the fabrications of compound semiconductor devices. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.