[IEEE 2016 Compound Semiconductor Week (CSW) [Includes 28th International Conference on Indium Phosphide & Related Materials (IPRM) & 43rd International Symposium on Compound Semiconductors (ISCS)] - Toyama, Japan (2016.6.26-2016.6.30)] 2016 Compound Semiconductor Week (CSW) [Includes 28th International Conference on Indium Phosphide & Related Materials (IPRM) & 43rd International Symposium on Compound Semiconductors (ISCS) - Relationship between Al content of AlGaN buffer layer on top of initial AlN nucleation layer on Si and vertical leakage current of AlGaN/GaN high-electron-mobility transistor structures