Improvement of ESD Level of GaN-Based LEDs Using Antiparallel Ga- and N-Polar Domains in p-GaN Layer

Electrostatic discharge (ESD) endurance ability of InGaN blue light-emitting diodes is significantly improved when antiparallel Ga- and N-polar domains coexist within the p-type GaN-layer region. The inversion of Ga to N polarity in this region, which is verified using convergent-beam electron diffraction, was induced by the stress accumulated in the underlying layers. A typical p-type GaN layer, which is composed of a periodical arrangement of Ga-polar domains (width, 450 nm) and antiparallel Ga- and N-polar domains (width, 150 nm), improves the negative human-body mode ESD 4000 V pass yields to greater than 90%.