Rapid thermal annealing effects on deep level defects in an n-type GaN layer grown by metalorganic chemical vapour deposition were characterized using deep-level transient spectroscopy. The samples were first characterized by current–voltage (I–V) and capacitance–voltage (C–V) measurements. The measurements showed that the barrier height of the as-grown sample was 0.74eV (I–V) and 0.95eV (C–V). However, the Schottky barrier height of the sample annealed at 800C increased to 0.84eV (I–V) and 0.99eV (C–V) in a nitrogen atmosphere for 1min. Further, it was observed that the Schottky barrier height slightly decreased after annealing at 900C. Deep-level transient spectroscopy results showed that the two deep levels were identified in as-grown sample (E1 and E3), which have activation energies of 0.19 and 0.80eV with capture cross-sections 2.06 x 10−17 and 7.68 x 10−18cm2, which could be related to point defects. After annealing at 700C, the appearance of one new peak (E2) at an activation energy of 0.49eV with capture-cross section σn = 5.43 x 10−17cm2, suggested that the E2 level was most probably associated with the nitrogen antisites. Thermal annealing at 800C caused the E1 and E3 levels to be annealed out, which suggested that they were most probably associated with the point defects. After annealing at 900C the same (E1 and E3) deep levels were identified, which were identified in as-grown n-GaN layer.

Effect of Rapid Thermal Annealing on Deep Level Defects in the Si-Doped GaN. V.R.Reddy, M.S.Reddy, P.K.Rao: Microelectronic Engineering, 2010, 87[2], 117-21