High-electron-mobility AlGaN∕AlN∕GaN heterostructures grown on 100-mm-diam epitaxial AlN/sapphire templates by metalorganic vapor phase epitaxy

Abstract

Al 0.26 Ga 0.74 N ∕ Al N ∕ Ga N heterostructures with 1-nm-thick AlN interfacial layers were grown on 100-mm-diam epitaxial AlN/sapphire templates and sapphire substrates by metalorganic vapor phase epitaxy. It was found that AlN/sapphire templates significantly enhanced the electron mobility of the two-dimensional electron gas (2DEG) confined at the GaN channel. This can be explained by the high-crystal-quality GaN channel realized by the use of epitaxial AlN/sapphire templates as substrates. The very high Hall mobilities of approximately 2100cm2∕Vs at room temperature and approximately 17000cm2∕Vs at 77K with a 2DEG density of approximately 1×1013∕cm2 were uniformly obtained for AlGaN∕AlN∕GaN heterostructures on 100-mm-diam epitaxial AlN/sapphire templates. The Hall mobility of AlGaN∕AlN∕GaN heterostructures on epitaxial AlN/sapphire templates reached a very high value of 25500cm2∕Vs at 15K.