ABSTRACT We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideality factors of Schottky contact are found in the range 0.35 eV (I-V), 0.73 eV (C-V) at 160 K and 0.63 eV (I-V), 0.61 eV (C-V) at 400 K, respectively. It is observed that the zero-bias barrier height decreases and ideality factor n increase with a decrease in temperature, this behaviour is attributed to barrier inhomogeneities by assuming Gaussian distribution at the interface. The calculated value of series resistance (Rs) from the forward I-V characteristics is decreased with an increase in temperature. The homogeneous barrier height value of approximately 0.71 eV for the Pd/Ti Schottky diode has been obtained from the linear relationship between the temperature-dependent experimentally effective barrier heights and ideality factors. The zero-bias barrier height ( ) versus 1/2kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of = 0.80 eV and = 114 mV for the mean barrier height and standard deviation have been obtained from the plot, respectively. The modified Richardson ln(I0/T2)- ( ) versus 1000/T plot has a good linearity over the investigated temperature range and gives the mean barrier height ( ) and Richardson constant (A*) values as 0.796 eV and 6.16 Acm-2K-2 respectively. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements is also interpreted.
Cite this paper
nullD. Reddy, M. Reddy, N. Reddy and V. Reddy, "Schottky Barrier Parameters of Pd/Ti Contacts on N-Type InP Revealed from I-V-T And C-V-T Measurements," Journal of Modern Physics, Vol. 2 No. 3, 2011, pp. 113-123. doi: 10.4236/jmp.2011.23018.
 E. H. Rhoderick and R. H. Williams, “Metal-Semiconductor Contacts,” 2nd Edition, Clarendon Press, Oxford, 1988.
 R. H. Williams and G. Y. Robinson, “Physics and Chemistry of III-V Compound Semiconductor Interfaces,” C. W. Wilmsen, Ed., Plenum Press, New York, 1985.
 R. T. Tung, “Recent Advances in Schottky Barrier Concepts,” Materials Science and Engineering: R, Vol. 35, No. 1-3, November 2001, pp. 1-138.
 K. Hattori and Y. Torii, “A New Method to Fabricate Au/n-type InP Schottky Contacts with an Interfacial Layer,” Solid-State Electronics, Vol. 34, No. 5, May 1991, pp. 527-531.
 Z. J. Horvath, V. Rakovics, B. Szentpali and S. Puspoki, “Schottky Junctions on n-Type InP for Zero Bias Microwave Detectors,” Physica Status Solidi C, Vol. 3, February 2003, pp. 916-921.
 T. S. Huang and R. S. Fang, “Barrier Height Enhancement of Pt/n-InP Schottky Diodes by P2S5/(NH4)2S Solution Treatment of the InP Surface,” Solid-State Electronics, Vol. 37, No. 8, August 1994, pp. 1461-1466.
 G. Eftekhari, “Electrical Characterization of Rapidly Annealed Ni and Pd/n-InP Schottky Diodes,” Semicon- ductor Science and Technology, Vol. 10, No. 8, May 1995, p. 1163.
 M. Soylu, B. Abay and Y. Onganer, “The Effects of Annealing on Au/Pyronine-B/MD n-InP Schottky Structure,” Journal of Physics and Chemistry of Solids, Vol. 71, No. 9, September 2010, pp. 1398-1403.
 Y. P. Song, R. L. Van Meirhaeghe, W. H. Laflere and F. Cardon, “On the Difference in Apparent Barrier Height as Obtained from Capacitance-Voltage and Current-Voltage- Temperature Measurements on Al/p-InP Schottky Barriers,” Solid-State Electronics, Vol. 29, No. 6, June 1986, pp. 633-638.
 J. H. Werner and H. H. Guttler, “Barrier Inhomogeneities at Schottky Contacts,” Journal of Applied Physics, Vol. 69, No. 3, February 1991, p. 1522.
 R. T. Tung, “Electron Transport at Metal-Semiconductor Interfaces: General Theory,” Physical Review B, Vol. 45, No. 23, June 1992, p. 13509.
 A. Gumus, A. Turut and N. Yalcin, “Temperature Dependent Barrier Characteristics of CrNiCo Alloy Schottky Contacts on n-Type Molecular-Beam Epitaxy GaAs,” Journal of Applied Physics, Vol. 91, No. 1, January 2002, p. 245.
 Y. G. Chen, M. Ogura and H. Okushi,“Temperature Dependence on Current-Voltage Characteristics of Nickel/ Diamond Schottky Diodes on High Quality Boron-Doped Homoepitaxial Diamond Film,” Applied Physics Letters, Vol. 82, No. 24, June 2003, p. 4367.
 M. K. Hudait, P. Venkateswaralu and S. B. Krupanidhi, “Electrical Transport Characteristics of Au/n-GaAs Schottky Diodes on n-Ge at Low Temperatures,” Solid- State Electronics, Vol. 45, No. 1, January 2001, pp. 133- 141.
 F. A. Padovani, “Semiconductors and Semimetals,” R. K. Willardson, A. C. Beer, Ed., Academic Press, New York, Vol. 7A, 1971.
 C. R. Crowell, “The Physical Significance of the T0 Anomalies in Schottky Barriers,” Solid-State Electronics, Vol. 20, No. 3, March 1977, pp. 171-175.
 R. T. Tung, J. P. Sullivan and F. Schrey, “On the Inhomogeneity of Schottky Barriers,” Materials Science and Engineering: B, Vol. 14, No. 3, August 1992, pp. 266-280.
 R. F. Schmitsdorf, T. U. Kampen and W. Monch, “Explanation of the Linear Correlation between Barrier Heights and Ideality Factors of Real Metal-Semiconductor Contacts by Laterally Nonuniform Schottky Barriers,” Journal of Vacuum Science & Technology B, Vol. 15, No. 4, July-August 1997, p. 1221.
 S. Zhu, R. L. van Meirhaeghe, C. Detavernier, F. Cardon, G. P. Ru, X. P. Qu and B. Z. Li, “Barrier Height Inhomogeneities of Epitaxial CoSi2 Schottky Contacts on n-Si (100) and (111),” Solid-State Electronics, Vol. 44, No. 4, April 2000, pp. 663-671.
 H. Cetin and E. Ayyildiz, “Temperature Dependence of Electrical Parameters of the Au/n-InP Schottky Barrier Diodes,” Semiconductor Science and Technology, Vol. 20, No. 6, May 2005, pp. 625-631.
 M. B. Reddy, A. A. Kumar, V. Janardhanam, V. Rajagopal Reddy and P. Narasimha Reddy, “Current–Voltage– Temperature (I–V–T) Characteristics of Pd/Au Schottky Contacts on n-InP (111),” Current Applied Physics, Vol. 9, No. 5, September 2009, pp. 972-977.
 M. Soylu and B. Abay, “Barrier Characteristics of Gold Schottky Contacts on Moderately Doped n-InP Based on Temperature Dependent I–V and C–V Measurements,” Microelectronic Engineering, Vol. 86, No. 1, January 2009, pp. 88-95.
 A. Ashok Kumar, V. Janardhanam, V. R. Reddy and P. Narasimha Reddy, “Evaluation of Schottky Barrier Parameters of Pd/Pt Schottky Contacts on n-InP (100) in Wide Temperature Range,” Superlattices and Microstructures, Vol. 45, No. 1, January 2009, pp. 22-32.
 F. E. Cimilli, H. Efeoglu, M. Saglam and A. Turat, “Temperature-Dependent Current-Voltage and Capacitance-Voltage Characteristics of the Ag/n-InP/In Schottky Diodes,” Journal of Material Science: Materials in Electronics, Vol. 20, February 2008, pp. 105-112.
 S. S. Naik and V. Rajagopal Reddy, “Analysis of Current-Voltage-Temperature (I-V-T) and Capacitance- Voltage-Temperature(C-V-T) Characteristics of Ni/Au Schottky Contacts on n-Type InP,” Superlattices and Microstructures, Vol. 48, No. 3, September 2010, pp. 330- 342.
 J. P. Sullivan, R. T. Tung, M. R. Pinto and W. R. Graham, “Electron Transport of Inhomogeneous Schottky Barriers: A Numerical Study,” Journal of Applied Physics, Vol. 70, No. 12, December 1991, p. 7403.
 S. Zeyrek, S. Altindal, H. Yuzer and M. Bulbul, “Current Transport Mechanism in Al/Si3N4/p-Si (MIS) Schottky Barrier Diodes at Low Temperatures,” Applied Surface Science, Vol. 252, No. 8, February 2006, pp. 2999-3010.
 S. K. Cheung and N. W. Cheung, “Extraction of Schottky Diode Parameters from Forward Current-Voltage Characteristics,” Applied Physics Letters, Vol. 49, No. 2, July 1986, p. 85.
 S. M. Sze, “Physics of Semiconductor Devices,” 2nd Edition, John Wiley and Sons, New York, 1981.
 S. Chand and J. Kumar, “Current Transport in Pd2Si/ n-Si(100) Schottky Barrier Diodes at Low Tempe- ratures,” Applied Physics A, Vol. 63, No. 2, March 1996, p. 171.
 N. Newman, M. V. Schilfgaarde, T. Kendelwicz, M. D. Williams and W. E. Spicer, “Electrical Study of Schottky Barriers on Atomically Clean GaAs(110) Surfaces,” Physical Review B, Vol. 33, No. 2, January 1986, p. 1146.
 Z. J. Horvath, “Comment on “Analysis of I-V Measurements on CrSi2 - Si Schottky Structures in a Wide Temperature Range,” Solid-State Electronics, Vol. 39, No. 1, January 1996, pp. 176-178.
 F. Pandovani and R. Stratton, “Field and Thermionic- Field Emission in Schottky Barriers,” Solid-State Electronics, Vol. 9, No. 7, July 1966, pp. 695-707.
 C. R. Crowell and V. L. Rideout, “Normalized Thermi- onic-Field (T-F) Emission in Metal-Semiconductor (Schottky) Barriers,” Solid-State Electronics, Vol. 12, No. 2, February 1969, pp. 89-105.
 Z. J. Horvath, V. Rakovics, B. Szentpali, S. Puspoki and K. Zdansky, “InP Schottky Junctions for Zero Bias Detector Diodes,” Vacuum, Vol. 71, No. 1-2, May 2003, pp. 113-116.
 J. Osvald, “New Aspects of the Temperature Dependence of the Current in Inhomogeneous Schottky Diodes,” Semiconductor Science and Technology, Vol. 18, No. 4, April 2003, p. L24.
 F. E. Jones, B. P. Wood, J. A. Myers, C. H. Daniels and M. C. Lonergan, “Current Transport and the Role of Barrier Inhomogeneities at the High Barrier n-InP Poly (Pyrrole) Interface,” Journal of Applied Physics, Vol. 86, No. 11, December 1999, p. 6431.
 M. K. Hudait, P. V. Venkateswaralu and S. B. Krupanidhi, “Electrical Transport Characteristics of Au/n- GaAs Schottky Diodes on n-Ge at Low Temperatures,” Solid-State Electronics, Vol. 45, No. 1, January 2001, pp. 133-141.
 J. H. Werner and H. H. Guttler, “Temperature Dependence of Schottky Barrier Heights on Silicon,” Journal of Applied Physics, Vol. 73, No. 3, February 1993, p. 1315.
 H. H. Guttler and J. H. Werner, “Influence of Barrier Inhomogeneities on Noise at Schottky Contacts,” Applied Physics Letters, Vol. 56, No. 12, March 1990, p. 1113.
 S. Zhu, R. L. Van Meirhaeghe, S. Forment, G. P. Ru, X. P. Qu and B. Z. Li, “Schottky Barrier Characteristics of Ternary Silicide Co1?xNixSi2 on n-Si(100) Contacts Formed by Solid Phase Reaction of Multilayer,” Solid- State Electronics, Vol. 48, No. 7, July 2004, pp. 1205- 1209.
 R. F. Schmitsdorf, T. U. Kampen and W. Monch “Correlation between Barrier Height and Interface Structure of Ag/Si(111) Schottky Diodes,” Surface Science, Vol. 324, No. 2-3, February 1995, pp. 249-256.
 L. E. Calvet, R. G. Wheeler and M. A. Reed, “Electron Transport Measurements of Schottky Barrier Inhomogeneities,” Applied Physics Letters, Vol. 80, No. 10, March 2001, p. 1761.
 Y. F. Tsay, B. Gong and S. S. Mitra, “Temperature Dependence of Energy Gaps of Some III-V Semiconductors,” Physical Review B, Vol. 6, No. 6, September 1972, p. 2330.