Electrical properties of rapidly annealed Au/Ta2O5/n-GaN metal-insulator-semiconductor (MIS) structure

B Prasanna Lakshmi, V Rajagopal Reddy

Abstract


The electrical properties of Au/Ta2O5/n-GaN metal-insulator-semiconductor (MIS) structure has been investigated as a function of annealing temperature by current-voltage (I-V) and capacitance-voltage (C-V) measurements. Measurements showed that theSchottky barrier height and ideality factor of the as-deposited Au/Ta2O5/n-GaN MIS structure are 0.93 eV (I-V) /1.05 eV (C-V) and 1.19, respectively. It is noted that the barrier height increases to 1.03 eV (I-V)/1.15 eV (C-V) and ideality factor decreases to 1.13 after annealing at 500 °C for 1 min under nitrogen ambient. However, it is found that the barrier heights slightly decreases to 0.99 eV/1.12 eV (C-V) for the MIS structure annealed at 600 oC. From the above observations, it is clear that the optimum annealing temperature for Au/Ta2O5/n-GaN MIS structure is 500 oC. Moreover, the barrier height values estimated from I-V and C-V measurements are different from each other. Norde method is also used to calculate the barrier heights of the MIS structure and the respective values are 0.90eV, 0.94eV, 0.99eV and 1.01 eV for as-deposited and structure annealed at 400 °C, 500 °C and 600 °C. These values are in good agreement with those estimated by I-V method.

Keywords


GaN, MIS diodes, barrier heights, ideality factors.

References


S.J. Pearton, C.R. Abernathy, F. Ren, Gallium Nitride Processing for Electronics, Sensors and Spintronics, Springer-Verlag,London, 2006.

K.W. Kim, S.D. Jung, D.S. Kim, H.S. Kang, K.S. Im, J.J. Oh,J.B. Ha, J.K. Shin, J.H. Lee, Effects of TMAH Treatment on Device Performance of Normally Off Al2O3/GaNMOSFET, IEEE Electron Device Lett. 32(2011)1376-1378.

K.S. Im, J.B. Ha, K.W. Kim, J.S. Lee, D.S. Kim, S.H. Hahm,J.H. Lee, Normally Off GaN MOSFET Based on AlGaN/GaNHeterostructure With Extremely High 2DEG Density Grown on Silicon Substrate, IEEE Electron Device Lett. 31 (2010)192-194.

Y. Nakano, T. Jimbo, Interface properties of thermally oxidized n-GaN metal-oxide-semiconductor capacitor. 82 (2003) 218-220.

T.H. Tsai, J.R. Huang, K.W. Lin, W.C. Hsu, H.I. Chen, W.C. Liu,Improved hydrogen sensing characteristics of Pt/SiO2/GaN Schottky diode, Sensor. Actuat. B-Chem. 129 (2008) 292-302.

C. Bae, C. Krug, G. Lucovsky, Electron trapping in metal-insulator-semiconductor structures on n-GaN with SiO2 and Si3N4 dielectrics, J. Vac. Sci. Technol. A 22(6) (2004) 2379-2383.

S.M. Sze, Physics of Semiconductor Devices,John Wiley & Sons, New York, 2007.

V. Rajagopal Reddy, M. Siva Pratap Reddy, B. Prasanna Lakshmi, A. Ashok Kumar, Electrical characterization of Au/n-GaN metal-semiconductor andAu/SiO2/n-GaN metal-insulator-semiconductor structures, J. Alloy. Comp. 509 (2011) 8001-8007.

S. Altindal, S. Karadeniz, N. Tugluoglu, A. Tataroglu, The role of interface states and series resistance on the I-V andC-V characteristics in Al/SnO2/p-Si Schottky diodes, Solid State Electron. 47 (2003) 1847-1854.

E.H. Rhoderick, R.H. Williams, Metal Semiconductor contacts, Clarendon, Oxford, 1998.

J.H. Werner, H.H. Guttler, Barrier inhomogeneities at Schottky contactsJ. Appl. Phys. 69 (1991) 1522-1533.

H.C. Card, E.H. Rhoderick, Studies of tunnel MOS diodes I. Interface effects in silicon Schottky diodes, J. Phys. D: Appl. Phys. 4 (1971) 1589-1601.

H. Norde, A modified forward I-V plot for Schottky diodes with high series resistance, J. Appl. Phys. 50(1979) 5052-5053.


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