Abstract
In this work, a PdAl/Au (20/30 nm) metal alloyed scheme was investigated for obtaining low resistance ohmic contacts to Mg-doped p-type GaN. The specific contact resistance (ρSCR) was determined using the circular-transmission-line pattern method between the metal contacts and p-type GaN by current–voltage (I–V) measurements. It is noted that the ρSCR of the as-deposited contact (1.23 × 10−2 Ω cm2) was enhanced upon rapid thermal annealing (RTA) at 600 °C (7.82 × 10−4 Ω cm2) for 1 min under N2 ambient. The effective Schottky barrier heights (SBHs) of the various annealed contacts were determined using the Norde and I–V methods. It is observed that the effective SBHs were dependent upon the RTA conditions. According to the X-ray diffraction and X-ray photoelectron spectroscopy results, the gallide-related phases were formed at the PdAl/Au/p-GaN interface such as Au7Ga2 and Ga3Pd5 upon RTA at 600 °C. These phases were responsible for obtaining low contact resistivity of the PdAl/Au contact. Atomic force microscopy results show that the surface morphology (root-mean-square, RMS) of the contact was reasonably smooth even after RTA at 600 °C with an RMS roughness of 0.714 nm. Observations indicate that the PdAl/Au metal alloyed contact was a suitable ohmic contact to p-type GaN for the development of commercially viable large-scale GaN-based microelectromechanical system applications.
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M.R. Zadeh, V.J. Gokhale, A. Ansari, M. Faucher, D. Theron, Y. Cordier, L. Buchaillot, J. Microelectromech. Syst. 23, 1252–1271 (2014)
E. Sillero, D.L. Romero, A. Bengoechea, M.A.S. Garcia, F. Calle, Phys. Stat. Sol. C 5, 1974–1976 (2008)
R. Szweda, Gallium Nitride and Related Wide Band Gap Materials and Devices, 2nd edn. (Elsevier Science, New York, 2000)
M.S.P. Reddy, B.-J. Kim, J.-S. Jang, Opt. Express 22, 908–915 (2014)
M.S.P. Reddy, H. Park, S.-M. Kim, S.-H. Jang, J.-S. Jang, J. Mater. Chem. C 3, 8873–8880 (2015)
M.S.P. Reddy, P.T. Puneetha, Y.-W. Lee, S.-H. Jeong, C. Park, Polym. Test 59, 107–112 (2017)
V. Cimalla, J. Pezoldt, O. Ambacher, J. Phys. D 40, 6389–6434 (2007)
S. Davies, T.S. Huang, M.H. Gass, A.J. Papworth, T.B. Joyce, P.R. Chalker, Appl. Phys. Lett. 84, 2566–2568 (2004)
Z. Yang, R.N. Wang, S. Jia, D. Wang, B. Zhang, K.M. Lau, K.J. Chen, Appl. Phys. Lett. 88, 041913 (2006)
S.J. Pearton, F. Ren, A.P. Zhang, K.P. Lee, Mater. Sci. Eng. R30, 55–212 (2000)
H.-S. Kang, M.S.P. Reddy, D.-S. Kim, K.-W. Kim, J.-B. Ha, Y.-S. Lee, H.-C. Choi, J.-H. Lee, J. Phys. D 46, 155101 (2013)
J.-S. Jang, S.-J. Park, T.-Y. Seong, J. Appl. Phys. 88, 5490–5492 (2000)
J.-S. Jang, T.-Y. Seong, Appl. Phys. Lett. 76, 2743–2745 (2000)
G. Greco, F. Iucolano, F. Roccaforte, Appl. Surf. Sci. 383, 324–345 (2016)
V. Rajagopal Reddy, S.-H. Kim, J.-O. Song, T.-Y. Seong, Solid-State Electron 48, 1563–1568 (2004)
H.-W. Jang, C.-M. Jeon, J.-L. Lee, Phys. Stat. Sol. C 0, 227–230 (2002)
J.K. Ho, C.S. Jong, C.C. Chiu, C.N. Huang, K.K. Shih, L.C. Chen, F.R. Chen, J.J. Kai, J. Appl. Phys. Lett. 86, 4491–4497 (1999)
H.K. Cho, T. Hossain, J.W. Bae, I. Adesida, Solid-State Electron 49, 774–778 (2005)
L.F. Voss, L. Stafford, R. Khanna, B.P. Gila, C.R. Abernathy, S.J. Pearton, F. Ren, I.I. Kravchenko, Appl. Phys. Lett. 90, 212107 (2007)
T. Han, T. Wang, X.W. GaN, H. Wu, Y. Shi, J. C. Liu, Korean. Phys. Soc. 65, 62–65 (2014)
S. Belahsene, G. Patriarche, D. Troadec, S. Sundaram, A. Ougazzden, A. Martinez, A. Ramdane, J. Vac. Sci. Technol. B 33, 010603 (2015)
M. Oh, W.-Y. Jin, H.-J. Jeong, M.-S. Jeong, J.-W. Kang, H. Kim, Sci. Rep. 5, 13483 (2015)
S. Zhao, H. Mcfavilen, S. Wang, F.A. Ponce, C. Arena, S. Goodnick, S. Chowdhury, J. Electron. Mater. 45, 2087–2091 (2016)
C.A.H. Gutierrez, Y. Kudriavtsev, E. Mota, A.G. Hernandez, A.E. Echavarria, V.S. Resendiz, Y.L.C. Moreno, M.L. Lopez, Nucl. Instrum. Methods Phys. Res. B 388, 35–40 (2016)
D. Qiao, L.S. Yu, S.S. Lau, J.Y. Lin, H.X. Jiang, T.E. Haynes, J. Appl. Phys. 88, 4196–4200 (2000)
J.K. Kim, J.H. Je, J.L. Lee, Y.J. Park, B.T. Lee, J. Electrochem. Soc. 147, 4645–4651 (2000)
J.-K. Kim, J.-L. Lee, J.-W. Lee, H.-E. Shin, Y.-J. Park, T. Kim, Appl. Phys. Lett. 73, 2953–2955 (1998)
L.-C. Chen, F.R. Chen, J.J. Kai, L. Chang, J.K. Ho, C.-S. Jong, C.C. Chiu, C.-N. Huang, C.-Y. Chen, K.-K. Shih, J. Appl. Phys. 86, 3826–3832 (1999)
T.S. Huang, J.G. Pang, J. Appl. Phys. 78, 5739–5744 (1995)
R. Hultgren, P.D. Desai, D.T. Hawkins, M. Gleiser, K.K. Kelley, Selected values of the thermodynamic properties of binary alloys (ASM, Materials Park, OH, 1973)
V. Rajagopal Reddy, Mater. Chem. Phys. 93, 286–290 (2005)
H. Norde, J. Appl. Phys. 50, 5052–5053 (1979)
T. Mori, T. Kozawa, T. Ohwaki, Y. Taga, S. Nagai, S. Yamasaki, S. Asami, N. Shibata, M. Koike, Appl. Phys. Lett. 69, 3537–3539 (1996)
E.H. Rhoderick, R.H. Williams, Metal-Semiconductor Contacts. (Clarendon, Oxford, 1988)
J. Sun, K.A. Rickert, J.M. Redwing, A.B. Ellis, F.J. Himpsel, T.F. Kuech, Appl. Phys. Lett. 76, 415–417 (2000)
V. Rajagopal Reddy, N.R. Reddy, C.-J. Choi, Solid-State Electron 49, 1213–1216 (2005)
J.-S. Jang, S.-J. Park, T.-Y. Seong, Appl. Phys. Lett. 76, 2898–2900 (2000)
V. Rajagopal Reddy, S.-H. Kim, J.-O. Song, T.-Y. Seong, Semicond. Sci. Technol. 18, 541–544 (2003)
Acknowledgements
This study was supported partially by the Energy technology development program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) which is funded by the Ministry of Trade, Industry and Energy, Republic of Korea (No. 20153010130320).
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Puneetha, P.T., Reddy, M.S.P., Lee, YW. et al. Electrical and interface properties of PdAl/Au metal alloyed ohmic contacts on p-type GaN for high-temperature MEMS devices. J Mater Sci: Mater Electron 28, 16903–16909 (2017). https://doi.org/10.1007/s10854-017-7609-8
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DOI: https://doi.org/10.1007/s10854-017-7609-8