Effect of high temperature AlN interlayer on the performance of AlGaN/GaN properties

A novel structure of AlGaN/GaN heterostructure which has a high temperature AlN interlayer (HT-AlN) in GaN buffer grown by metal organic chemical vapor deposition(MOCVD) on c-plane sapphire substrate has been researched. It is found that both electron mobility and sheet carrier concentration are increased by the HT-AlN interlayer compared to AlGaN/GaN heterostructure without HT-AlN interlayer. The sheet carrier concentration and Hall mobility measured by Hall increased from 1.446×10¹³ cm^-2 and 1019 cm²/v·s to 1.605×10¹³cm^-2 and 1036 cm²/v·s, respectively, hence the sheet resistance decreased from 424¿/¿ to 376¿/¿.