Patent ID: 7983889

Claim:
A simulation method comprising: a first step of inputting model parameters of a lateral diffused MOSFET (LDMOSFET) from an input device, wherein the model parameters include at least a resistance value of overlap region of a source side and a resistance value of a drift region; a second step of inputting voltages to be applied to the LDMOSFET from the input device, wherein the voltages include a gate-to-source voltage, a source-to-drain voltage, and a bulk-to-source voltage; a third step of inputting an initial value of a drain-to-source current of the LDMOSFET from the input device; a fourth step of calculating, using a central processing unit, the resistance value in the drift region of the LDMOSFET on the basis of at least some of the model parameters input in the first step and at least some of the voltages set in the second step; a fifth step of calculating, using the central processing unit, a voltage drop caused by the resistance value in the drift region of the LDMOSFET on the basis of the calculated resistance value in the drift region; a sixth step of calculating, using the central processing unit, a potential of a source end of the LDMOSFET using a voltage that considers the calculated voltage drop by solving a Poisson's equation by iterative calculation; a seventh step of calculating, using the central processing unit, a potential of a channel end of the LDMOSFET using the voltage that considers the calculated voltage drop by solving the Poisson's equation by iterative calculation; an eighth step of calculating, using the central processing unit, the drain-to-source current of the LDMOSFET; a ninth step of determining whether an absolute value of a difference between the drain-to-source current used in calculation in the fifth step and the drain-to-source current calculated by the central processing unit in the eighth step is not more than a predetermined calculation error; a 10th step of calculating charge densities and capacitances by the central processing unit when the absolute value is determined in the ninth step to be smaller than the calculation error; and an 11th step of substituting the drain-to-source current calculated in the eighth step into the drain-to-source current to be used for calculation in the fifth step by the central processing unit when the absolute value is determined in the ninth step to be not less than the calculation error, wherein after executing the 11th step, the fifth to ninth steps are repeated.