Patent ID: 8028261
Filing Date: 2011-09-27
Classification: G06F

Abstract:
1. A method to utilize a computer to predict a substrate current in a device, comprising: determining whether a drain voltage of the device is equal to or higher than a prescribed first critical value; and then setting an additional substrate current of the device to zero if the drain voltage is lower than the first critical value; and then determining whether a gate voltage of the device is equal to or higher than a prescribed second critical value if the drain voltage is equal to or higher than the first critical value; and then setting the additional substrate current to zero if the gate voltage is lower than the second critical value; and then setting, by using the computer, the additional substrate current to a value obtained by multiplying a second power of a difference between the second critical value and the gate voltage, the drain voltage, and a proportional constant if the gate voltage is equal to or greater than the second critical value; and then adding the additional substrate current to a substrate current of the device obtained through MOSFET device modeling, wherein the first critical value is set to the drain voltage when a change in the substrate current appears, depending on the gate voltage, and wherein the second critical value is set to the gate voltage when a decreasing substrate current starts to increase.