The influence of image forces on the extraction of physical parameters in Schottky barrier diodes

We present a method for extraction of the Schottky barrier diode parameters from current–voltage (I–V) characteristics in the presence of barrier height changes with voltage induced by image forces. The techniques, which allow for the inclusion of a series resistance $R_s$ yield the built-in voltage $V_{\mathrm{bi}},$ the saturation current $I_S$ (zero bias barrier height ${\Phi }_B)$ the image force potential ${\mathrm{\Delta \Phi }}_B,$ the donor concentration $N_D$ and the voltage dependence of the ideality factor $\mathrm{\beta .}$ The method separates the effects on the I–V characteristic of an image force from the effect of current flow mechanisms other than thermionic emission. The proposed procedure determines a general voltage dependence of the effective ideality factor $\mathrm{\beta (V)}$ which is not limited to Schottky diodes but is also applicable to other diode types based on PN junction.