TY - JOUR
T1 - Electrical characteristics of N-polar (0001) p-type GaN Schottky contacts
AU - Aoki, Toshichika
AU - Tanikawa, Tomoyuki
AU - Katayama, Ryuji
AU - Matsuoka, Takashi
AU - Shiojima, Kenji
N1 - Funding Information:
Part of this work was supported by a Grant-in-Aid for Scientific Research (C) 15K05981 from the Ministry of Education, Culture, Sports, Science and Technology. This work was partly performed under the Inter-university Cooperative Research Program of the Institute for Materials Research, Tohoku University (Proposal No. 15K0081).
Publisher Copyright:
© 2016 The Japan Society of Applied Physics.
PY - 2016/4
Y1 - 2016/4
N2 - The electrical characteristics of Ni/N-polar p-GaN Schottky contacts were investigated in comparison with those of Ga-polar contacts. The Schottky barrier heights were obtained to be 0.91, 1.24, and 1.30 eV from the current-voltage (I-V), capacitance-voltage, and photoresponse results, respectively. These values of the N-polar samples were more than 1 eV lower than those of the Ga-polar samples. Hence, it was suggested that a Ni contact on N-polar p-GaN has a possible advantage in forming better ohmic electrodes. In addition, we also found that no memory effect, which was caused by the charge and discharge of surface defects [Ga vacancies (VGa)], was observed in the I-V characteristics, and no single peak of VGa was observed in the high-temperature isothermal capacitance transient spectroscopy spectrum. Therefore, it is suggested that the topmost N atomic layer can suppress the Ga out-diffusion.
AB - The electrical characteristics of Ni/N-polar p-GaN Schottky contacts were investigated in comparison with those of Ga-polar contacts. The Schottky barrier heights were obtained to be 0.91, 1.24, and 1.30 eV from the current-voltage (I-V), capacitance-voltage, and photoresponse results, respectively. These values of the N-polar samples were more than 1 eV lower than those of the Ga-polar samples. Hence, it was suggested that a Ni contact on N-polar p-GaN has a possible advantage in forming better ohmic electrodes. In addition, we also found that no memory effect, which was caused by the charge and discharge of surface defects [Ga vacancies (VGa)], was observed in the I-V characteristics, and no single peak of VGa was observed in the high-temperature isothermal capacitance transient spectroscopy spectrum. Therefore, it is suggested that the topmost N atomic layer can suppress the Ga out-diffusion.
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U2 - 10.7567/JJAP.55.04EJ09
DO - 10.7567/JJAP.55.04EJ09
M3 - Article
AN - SCOPUS:84963657020
VL - 55
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 4
M1 - 04EJ09
ER -