Abstract
Group III-Nitride semiconductors are of considerable interest because of their potential for optoelectronic applications such as light-emitting diodes（LEDs） and laser diodes （LDs）in the visible light regions. The dry etching process is one of the critical steps in the fabrication of nitride-based LEDs.A study based on Taguchi experimental design was carried out to investigate the etch characteristics of GaN/InGaN quantum well light emitting diodes using a high density inductively coupled plasma of BCl3/Cl2-based chemistry. The process parameters studied include inductive power, bias power, BCl3/Cl2 gas ratio and chamber pressure. The etch characteristics measured were etch rate, surface roughness, side-wall angle and etch selectivity to SiO2 mask.It was found that the variations in the bias power had maximum effect on the etch rate whereas the pressure affected etch rate the least. Anisotropic profiles were generally achieved over a wide range of parameters with low substrate bias. Certain interesting phenomena such as “grass” and sidewall striations were observed. Nearly smooth etched surface were observed for most etch conditions. The etch mechanisms of different etch conditions on both GaN grown by MBE and MOCVD and the differences of surface roughness before and after etching will also be discussed.