Epitaxial growth of GaN-based heterostructures of high quality on Si substrates using a large lattice-mismatch induced stress control technology

A large lattice-mismatch induced stress control technology with a low Al content AlGaN layer has been used to grow high quality GaN layers on Si substrates. The use of this technology allows for high mobility AlGaN/GaN heterostructures with electron mobility of 2240 cm²/Vs. It is demonstrated that the large lattice mismatch between the low Al content AlGaN layer and AlN buffer layer could effectively promote the edge dislocation inclination with relatively large bend angles and therefore significantly reduce the dislocation density in the GaN epilayer.