Improvements in Microstructure and Leakage Current of High-In-Content InGaN p-i-n Structure by Annealing

The effects of annealing on the microstructure and electrical properties of a high-In-content InGaN p-i-n structure have been investigated. After the annealing under optimal conditions, the surface roughness of the InGaN structure reduces pronouncedly, accompanied by an improvement in the crystalline quality of the p-GaN cap layer, and an incorporation process of segregated In atoms into the p-InGaN layer occurs simultaneously and results in an increase of about 3% indium content. Furthermore, the annealing significantly improves the pn-junction behavior of the InGaN p-i-n structure by two orders of magnitude reduction in the reverse leakage current.