Study of current–voltage–temperature ( I– V– T) and capacitance–voltage–temperature ( C– V– T) characteristics of molybdenum Schottky contacts on n-InP (1 0 0)

Abstract

The variation in electrical characteristics of Mo/n-InP (1 0 0) Schottky contacts have been systematically investigated as a function of temperature using current–voltage ( I– V) and capacitance–voltage ( C– V) measurements in the temperature range 200–400 K. The diode parameters like ideality factor n and zero-bias barrier height Φ b0 have been found to be strongly temperature dependent and while the zero-bias barrier height Φ b0 ( I– V) increases, the ideality factor n decreases with increasing temperature. The I– V characteristics are analyzed on the basis of thermionic emission (TE) theory and the assumption of Gaussian distribution of barrier heights due to barrier inhomogeneities that prevail at the metal–semiconductor interface. The zero-bias barrier height Φ b0 versus 1/2 kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of Φ ¯ b 0 = 0.93 eV and σ 0 = 144 meV for the mean barrier height and zero-bias standard deviation have been obtained from this plot, respectively. The modified Richardson plot has given mean barrier height Φ ¯ b 0 and Richardson constant ( A**) as 0.85 eV and 2.54 A cm −2 K −2, respectively. The temperature dependence of the I– V characteristics of the Mo/n-InP Schottky diode have been successfully explained on the basis of thermionic emission (TE) mechanism with Gaussian distribution of the Schottky barrier heights (SBHs).