The barrier height inhomogeneity in AL/P-SI schottky barrier diodes with native insulator layer

The I-V-T characteristics of Al/p-Si Schottky barrier diodes with native insulator layer were measured in the temperature range of 150-375 K. Experimental I-V data reveals an increase of barrier height(FB0) but decrease of ideality factor(n) with increase in temperature. The conventional Richardson plot exhibits nonlinearity below 210 K with the linear portion corresponding to activation energy of 0,241 eV. This value is much lower than the known value of 32 A/cm2K2 for holes in p-type Si. Such behavior is attributed to Schottky barrier inhomogeneities by assuming a Gaussian distribution of barrier heights (BHs) due to barrier height inhomogeneities that prevail at interface. Thus, a modified ln(Io/T2)-q2σo2/2k2T2 vs q/kT plot gives ΦB0 and A* as 1.050 eV and 40.03 A/cm2K2, respectively. This value 40.03 A/cm2K2 is very close to the theoretical value of 32 A K-2 cm-2 for p-type Si