Patent ID: 6954723

Claim:
A device simulation method comprising: calculating a band gap narrowing of a semiconductor and an ionization rate of an impurity in an equilibrium state; calculating a movable electric charge density contributing to transportation of an electric charge inside the semiconductor by solving a Poisson equation and a movable electric charge continuous equation based on the calculated ionization rate in the equilibrium state; calculating said band gap narrowing and said ionization rate in a non-equilibrium state, taking presence of a potential into consideration, based on the calculated movable electric charge density; and repeating the calculation of the movable electric charge density by solving the Poisson equation and the movable electric charge continuous equation based on the ionization rate and the band gap narrowing in said non-equilibrium state, and the calculation of said band gap narrowing and said ionization rate based on the calculation result, until the ionization rate and the band gap narrowing in said non-equilibrium state converge.