Failure mechanisms associated with the fabrication of InGaN-based LEDs

In this paper, we report on the device fabrication and characterization of InGaN/GaN multiple quantum well light-emitting diodes (LEDs) on sapphire substrates. Devices that showed nonrectifying behavior have been investigated and it is suggested that metal migration along defect tubes is the likely cause of this behavior, It is recommended to use lower alloying temperatures for the p-contact metallization to avoid this type of failure. Deposition and subsequent removal of sputtered oxide was also found to have a highly detrimental effect on the p-contact quality.