TITLE:
Schottky Barrier Parameters of Pd/Ti Contacts on N-Type InP Revealed from I-V-T And C-V-T Measurements
AUTHORS:
D. Subba Reddy, M. Bhaskar Reddy, N. Nanda Kumar Reddy, V. Rajagopal Reddy
KEYWORDS:
Schottky Barrier Parameters, I-V-T and C-V-T Measurements, Pd/Ti Schottky Contacts, N-Type
InP, Gaussian Distribution
JOURNAL NAME:
Journal of Modern Physics,
Vol.2 No.3,
March
31,
2011
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.