Thermal Annealing Behaviour of Several Deep Levels in GaInNAs Grown by Molecular Beam Epitaxy

Abstract

The X-Ray Diffraction (XRD) and Deep-Level Transient Fourier Spectroscopy (DLTFS) techniques are used to investigate the thermal annealing behaviour of at least 5 deep level in two samples of Ga98.7In1.3N0.43As99.57, one medium doped with Si (2 × 1016cm–3) and the second one heavily doped with Si (1 × 1018cm–3 grown by molecular beam epitaxy (MBE). The thermal annealing study was done at 650C, 700C, 750C and 800C for 5 min. One main electron trap with activation energy of 0.976eV, a capture cross section of 5.67 ×10–11cm2 and a density of 3.17 × 1014cm–3 is detected for the medium doped as-grown sample. For the heavily doped sample one main electron trap with activation energy of 0.35eV, a capture cross section of 7.12 × 10–14cm2 and a density of 2.25 × 1015cm–3 is detected. For the heavily doped sample, this electron trap only decreases its density as the annealing temperature increases. No more deep centres appear with annealing. For the medium doped sample, the main electron trap decreases its density as the annealing temperature increases, but unlike the heavily doped sample, four more deep centres appear, depending on the annealing temperature. XRD study does not show any structural change for the heavily doped sample, but it does for the medium doped sample only for annealing at 700C. This strongly suggests that the increasing presence of Si strongly eliminates the possibility of electron traps and gives more structural strength to the crystal. Their annealing temperature dependence and possible origin of the electron traps are reported for the first time.