PL Intensity and Life-Time Enhancements of the n-GaN Light-Emitting Diode During the Device Fabrication

Abstract

Abstract:In this study, a thermal annealing process was used for evaluating the recovering effect of the surface bombardment in the plasma etching process. After inductively coupled plasma (ICP) etching, the n-GaN samples were heated and annealed in an N 2 ambient, which influenced the electrical and photonic characteristics of the devices under test. Eventually, it showed that the resistance improved after the annealing treatment, particularly at a temperature of 550 °C. Furthermore, photoluminescence (and emission-intensity degradation) measurements yielded the same results for these n-GaN LED samples, which increased to 200% (8%) of that of a nonannealing reference group at this annealing temperature. However, this annealing treatment did not completely repair the luminescence intensity and emission life-time because of the formation of deep-level point defects on the n-GaN sample surface during the fabrication process.