Comparative study of unintentionally doped and Si-doped multi-channel AlGaN/GaN heterostructures

Unintentionally doped and Si-doped multi-channel AlGaN/GaN heterostructures grown on sapphire substrates were investigated. After Si doping in the multi-channel region, the atomic force microscopy measurements showed that the surface root mean square roughness of the multi-channel AlGaN/GaN heterostructure has increased and that many V-shaped defects were formed. Transmission electron microscopy images further indicated the presence of dislocation termination in the multi-channel region of the Si-doped multi-channel AlGaN/GaN heterostructure. Both the formation mechanism of V-shaped defects and the principle of dislocation blocking in the Si-doped multi-channel region are analyzed.

Automated summary

Unintentionally doped and Si-doped multi-channel AlGaN/GaN heterostructures grown on sapphire substrates were studied. The results showed that Si doping increased the surface roughness and formed V-shaped defects in the multi-channel AlGaN/GaN heterostructure. Transmission electron microscopy images revealed dislocation termination in the Si-doped multi-channel region. The formation mechanism of V-shaped defects and the principle of dislocation blocking in the Si-doped multi-channel region were analyzed.