Electrical properties of strained AlN/GaN superlattices on GaN grown by metalorganic vapor phase epitaxy

We have studied the temperature dependence of electrical properties of crack-free strained AlN/GaN superlattices (SLs) on GaN grown by metalorganic vapor phase epitaxy. A (0001) sapphire substrate was used. A single AlN on GaN and one and five pairs of AlN/GaN superlattices were grown using N2 carrier gas. The thicknesses of AlN and GaN in the superlattices were 1 and 5 nm, respectively. Hall measurements were performed at 295–20 K. The five pairs of AlN/GaN SLs on GaN showed an electron mobility of 9925 cm2/V s and a sheet carrier density of 1.14×1012 cm−2 at 20 K, and 1354 cm2/V s and 1.14×1012 cm−2 at 295 K.