We describe a technique to extract device parameters of a Schottky barrier diode whose barrier height is bias dependent and which contains a linear series resistance. The extracted parameters include the saturation current (zero bias barrier height), the voltage dependence of the barrier height and of the ideality factor as well as series resistance. The technique makes use of forward biased current-voltage (I-V) characteristic and voltage-dependent differential slope curve α = d(lnI)/d(lnV). The method is verified using simulated and experimental I-V curves of an Al-pSi structure. The proposed procedure is not limited to Schottky barrier diodes but may be applied to other diode types based on P-N junction.