MBE-grown buffer with high breakdown voltage for nitride HEMTs on GaN template

The paper presents a molecular beam epitaxial (MBE) grown buffer for nitride HEMT. The samples were grown at the same thermocouple temperature of 660°C. GaN buffer layer was directly grown on the GaN template. In the secondary ion mass spectrometry (SIMS) measurements, unexpected silicon and oxygen impurity atoms at the template surface that caused the buffer leakage were identified.