Deep level defects in n-type GaN grown by molecular beam epitaxy

Abstract

Deep-level transient spectroscopy has been used to characterize electronic defects in n-type GaN grown by reactive molecular-beam epitaxy. Five deep-level electronic defects were observed, with activation energies E 1 ϭ0.234Ϯ0.006, E 2 ϭ0.578Ϯ0.006, E 3 ϭ0.657Ϯ0.031, E 4 ϭ0.961Ϯ0.026, and E 5 ϭ0.240Ϯ0.012 eV. Among these, the levels labeled E 1 , E 2 , and E 3 are interpreted as corresponding to deep levels previously reported in n-GaN grown by both hydride vapor-phase epitaxy and metal organic chemical vapor deposition. Levels E 4 and E 5 do not correspond to any previously reported defect levels, and are characterized for the first time in our studies.

Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition

“…Therefore, in our case, we believe that the plasma treatments do not cause any meaningful increase in dislocation density, even under an etching biasvoltage of Ϫ150 V. Trap D, with E T ϭ0.23-0.27 eV and n ϭ(1 -2)ϫ10 Ϫ15 cm 2 , has been observed in thin GaN layers by many groups, using various techniques, including hydride vapor phase epitaxy ͑HPVE͒, [8][9][10] MOCVD, [11][12][13] and MBE. 14,15 Three of these studies are consistent with the proposition that trap D is at least sometimes related to threading dislocations. For example, the concentration of trap D in HVPE GaN increases with increasing dislocation density, corresponding to decreasing epilayer thickness.…”

Radiation-induced defects in GaN bulk grown by halide vapor phase epitaxy

“…[14][15][16] There have been different reports on this trap; however, its origin is still under debate. By using two kinds of precursors (TMGa and TEGa), Lee et al 17 proposed D2 to be carbon or hydrogen related defects.…”

Analysis of Deep Level Defects in GaN p-i-n Diodes after Beta Particle Irradiation

“…The electron trap labeled E1 and E1i with thermal activation energy ET ≈ (0.63-0.66 eV) have signatures very close to the traps commonly observed in undoped and Si doped GaN. Some authors attribute the trap either to a single defect (vacancy) or to VGa-ON complex [8][9][10]. Haase et al invoke a native defect in GaN [11].…”