Response to 'Comment on 'Enhancement of Schottky barrier height on AlGaN/GaN heterostructure by oxidation annealing'' Appl. Phys. Lett. 83, 5319 (2003)

摘要

In our previous letter, the oxidation annealing and subsequent aqua-regia treatment of AlGaN/GaN heterostructure improved the Schottky barrier height of Pt Schottky contact. In Figs. 2 and 3 of Ref. 1, it was shown that the Ga 3d core level and valence band spectra shifted by 0.11 and 0.17 eV with the aqua-regia treatment, respectively. In our interpretation, the band gap of AlGaN was assumed to be constant independent of the surface treatment. Thus, the band bending of 0.17 eV in Fig. 5 of Ref. 1 was deduced from the shift of valence band spectra. However, Lin and Wu determined the band bending using the change of Ga 3d core level spectrum, corresponding to 0.11 eV. This yields the reduction of the AlGaN band gap by 0.06 eV in the surface treated sample. They argued that the band gap of AlGaN tends to decrease with an increase in the electron affinity of AlGaN.