Thin Solid Films, vol.531, pp.436-441, 2013 (SCI-Expanded)
In order to evaluate current conduction mechanism in the Au/p-InP Schottky barrier diode (SBD), some electrical parameters such as the barrier height (Φbo) and ideality factor (n) have been obtained from the forward bias current-voltage (I-V) characteristics. The I-V measurements show that n is close to unity at room temperature, indicating that the main mechanism of current flow through the SBD is thermionic emission (TE).On the other hand, the particular contact fabrication process produces a relatively high value of barrier height (0.78 eV) at room temperature. The variation of Φbo with temperature has been obtained as 4 × 10 - 4 eV K- 1, which is close to the temperature coefficient of the band-gap of InP. It has been found that Φbo and n values of the SBD are temperature dependent below room temperature by using TE theory. Φbo increases and n decreases with increasing temperature. The assumption of a double Gaussian distribution of the Schottky barrier height has been applied due to barrier inhomogeneities that prevail at the metal-semiconductor interface giving mean barrier heights of 0.98 and 0.84 eV and standard deviations of 88 and 53 mV for 80-180 K and 180-320 K temperature regions, respectively. The values of mean barrier height and Richardson constant (A*) using the modified Richardson ln(I0/T 2) - (q2σs2/2k 2T2) plot have been found as 1.00 eV, 77.52 A/cm 2 K2 for 80-180 K and 0.83 eV, 56.76 A/cm2 K2 for 180-320 K, respectively. A*values are in close agreement with the value of 60 A/cm2 K2 known for p-type InP. © 2013 Elsevier B.V.