Deep level traps in semi-polar n-GaN grown on patterned sapphire substrate by metalorganic vapor phase epitaxy

Deep level traps in the low dislocation density, 5.1x10(7)cm(-2), semi-polar GaN (11-22), grown on patterned sapphire substrate was characterized for the first time using deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS). DLTS revealed two deep levels E-T1=E-C-0.24eV and E-T2=E-C-0.41eV in the semi-polar GaN layer. The dominant trap E-T1=E-C-0.24eV with a density of 6.1x10(14)cm(-3), is documented in c-plane and m-plane GaN. It is attributed to V-N. DLOS revealed two deep level traps E-T3=E-C-1.20eV and E-T4=E-C-3.26eV. The dominant level E-T4=E-C-3.26eV is also observed in non-polar m-plane GaN grown on sapphire and it is attributed to C-N acceptor-like state. The total trap density of the semi-polar GaN is about 2x10(16)cm(-3), which is comparable with that found in c-plane GaN.