Effects of Growth Temperature on Structural and Electrical Properties of InAIN/GaN Heterostructures Grown by Pulsed Metal Organic Chemical Vapor Deposition on c-Plane Sapphire

摘要

The authors report the effects of growth temperature on the structural and electrical properties of InAIN/GaN heterostructures, which were grown on c-plane sapphire substrates by pulsed metal organic chemical vapor deposition (PMOCVD). High resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM) measurements indicate that the quality of InAIN barrier is strongly dependent on the growth temperature. It is observed that the indium composition and surface root-mean-square (rms) roughness value of InAIN barrier decrease with increasing the growth temperature, and a nearly lattice-matched InAIN/GaN heterostmcture with a smooth surface is obtained at 710℃. As a consequence, the variation of structural properties of InAIN barrier influences the electrical properties of InAIN/GaN heterostructures, and high electron mobility in excess of 1400 cm~2 V~(-1) s~(-1) is achieved at an optimized growth temperature window of InAIN barrier layer between 710 and 730℃.