Semiconductor junction model and method for use in a circuit modeling tool

A semiconductor junction (13) is represented as a junction capacitance (21) in parallel with a junction resistance (23) and junction inductance (22). The junction capacitance, junction resistance and junction inductance are functions of the voltage across the semiconductor junction and are determined using a probability of charge stored across the semiconductor junction. Junction parameters are determined with parameter extraction processes. A circuit simulation tool is used to simulate the performance of a circuit that includes the semiconductor junction. Accordingly, diode junctions are more accurately modeled above their built-in potential and below their reverse break-down voltage.