Defect Formation in GaN introduced during Plasma Processing
S. Nakamura, M. Suda, M. Suhara, and T. Okumura
Division of Electrical and Electronic Engineering,
1-1 Minami Ohsawa,
Keywords: hydrogen, argon, nitrogen, plasma, passivation, gallium nitride
We have studied the electrical characteristics of n-GaN exposed to plasma. In the case of hydrogen plasma, the decrease in leakage current as well as carrier density was clearly observed in the planer-type n-GaN Schottky diodes. In addition the decrease in carriers was also observed in the n-GaN layer exposed to argon plasma, while the increase in leakage current was observed. Thus, these results indicate that hydrogen atoms passivate the defects in the subsurface region. On the other hand, any notable change in electrical properties was not observed in the case of nitrogen plasma treatment. Therefore, it is considered that the decrease in carrier density was related to the intrinsic defects associated with deficiency of nitrogen atoms.