Analysis of current–voltage–temperature (––) and capacitance–voltage–temperature (––) characteristics of Ni/Au Schottky contacts on n-type InP

Abstract: The current–voltage (–) and capacitance–voltage (–) characteristics of Ni/Au/n-InP (111) Schottky contacts have been studied in the temperature range 210–420 K in steps of 30 K. The forward – characteristics are analyzed on the basis of thermionic emission (TE) theory assuming a Gaussian distribution of the barrier heights (BHs). The estimated Schottky barrier height (SBH) of an Ni/Au Schottky contact is in the region of 0.38 eV (–), 0.93 eV (–) at 210 K and 0.70 eV (–), 0.73 eV (–) at 420 K, respectively. The calculated ideality factor of an Ni/Au Schottky barrier diode (SBD) varies from 3.25 at 210 K to 1.99 at 420 K. It has been observed that the ideality factor decreases while the zero-bias BH increases with increasing temperature. This behavior has been interpreted by the assumption of a Gaussian distribution of BHs due to barrier inhomogeneities that prevail at the metal–semiconductor interface. The zero-bias BH versus plot has been drawn to obtain evidence of the Gaussian distribution of the BHs. The mean value of obtained is 1.01 eV, with standard deviation . From the modified Richardson plot, the mean BH is 0.97 eV and the Richardson constant () is 4.507 A cm−2 K−2, which is close to the theoretical value of 9.4 A cm−2 K−2. The discrepancy between SBHs obtained from the – and – measurements is also explained. The experimentally observed value of 5.235 meV agrees very well with the theoretically calculated value of . [ABSTRACT FROM AUTHOR]