Structural and electrical characterization of InN, InGaN, and p-InGaN grown by metal-modulated epitaxy

Abstract

InN, high indium content InGaN, and Mg-doped InGaN were grown by metal modulated epitaxy (MME). Transient reflection high-energy electron diffraction intensities were analyzed during the growth of InN and found to be similar to that previously reported for GaN and AlN. The x-ray diffraction rocking curve and background electron concentration of InN grown by MME were found to be respectable in comparison to recent reports in literature. InGaN alloys grown by MME were also investigated, and a method for detecting indium surface segregation was demonstrated. It was found that the shutter modulation scheme could be modified to prevent phase separation by indium surface segregation, and a range of single-phase InGaN samples with indium contents throughout the miscibility gap were grown. Using the discovered method of suppressing phase separation, several p-InxGa1 − xN samples were grown with indium contents from x = 0 to 0.22. A maximum hole concentration of 2.4 × 1019 cm−3 was detected by Hall effect characterization, demonstrating feasibility of these p-InGaN layers for use in several device applications.