Electron Traps in n-GaN Grown on Si (111) Substrates by MOVPE

Abstract

ABSTRACTDeep level electron traps in n-GaN grown by metal organic vapor phase epitaxy (MOVPE) on Si (111) substrate were studied by means of deep level transient spectroscopy (DLTS). The growth of n-GaN on different pair number of AlN/GaN superlattice buffer layers (SLS) system and on c-face sapphire substrate are compared. Three deep electron traps labeled E4 (0.7-0.8 eV), E5 (1.0-1.1 eV), were observed in n-GaN on Si substrate. And the concentrations of these traps observed for n-GaN on Si are very different from that on sapphire substrate. E4 is the dominant of these levels for n-GaN on Si substrate, and it behaves like point-defect due to based on the analysis by electron capture kinetics, in spite of having high dislocation density of the order of 1010 cm−3.