Patent ID: 6559672
Filing Date: 2003-05-06
Classification: G01R,H01L

Abstract:
A computer readable storing medium storing a characteristic evaluation program of insulated gate type transistors for making a computer evaluate, from at least two insulated gate type transistors that differ from each other only in mask channel width, the characteristic of a second insulated gate type transistor having a more narrow mask channel width using the characteristic of a first insulated gate type transistor having a wider mask channel width as a reference, wherein said characteristic evaluation program is installed in a computer so that said computer functions as a characteristic evaluation apparatus for insulated gate type transistors, said apparatus comprising:threshold voltage estimation means for extracting a threshold voltage of said first transistor, for estimating the threshold voltage of said second transistor, and for employing a value as estimated, as a first estimated value; extraction means in which (i) a difference between a gate voltage of said first transistor and said extracted threshold voltage of said first transistor is defined as a first gate overdrive, and a difference between a gate voltage of said second transistor and said first estimated value is defined as a second gate overdrive, (ii) under the condition that said first and second gate overdrives are the same in an X-Y plane whose X-axis is said mask channel width and whose Y-axis is source-drain resistance, a virtual point at which a change in Y coordinate value is estimated to be approximately zero even if said first and second gate overdrives are finely changed, is extracted from points on a straight line passing through a first point whose X coordinate is said mask channel width of said first transistor and whose Y coordinate is said source-drain resistance, of said second transistor, and a second point whose X coordinate is said mask channel width of said second transistor and whose Y coordinate is said source-drain resistance of said first transistor, (iii) values of the X coordinate and Y coordinate at said virtual points are defined as second and third estimated values, respectively, and (iv) a slope of said straight line at said virtual points is extracted and a value of said slope is employed as a fourth estimated value; threshold voltage determination means for determining a true threshold voltage of said second transistor by using said first to fourth estimated values; and channel narrowing determination means for determining a difference between said mask channel width and an effective channel width based on said true threshold voltage.