Patent ID: 6246973
Filing Date: 2001-06-12
Classification: G06F

Abstract:
A modeling method of MOSFET for modeling an electrical characteristic of a MOSFET in accordance with an effective value of channel width (We), said MOSFET having a channel-forming gate oxide film, a gate electrode disposed on said gate oxide film, and a field oxide film extending continuously across both sides of said gate oxide film, wherein:said effective value of channel width (We) is determined according to the following equation:We=W-.DELTA.W1+.DELTA.W2+.DELTA.W3where W denotes a design value for the channel width, and .DELTA.W1, .DELTA.W2, and .DELTA.W3 denote correction values determined, respectively by:(a) as W is increased from zero, the gate-to-source transistor gain is substantially zero when W is scaled down; a difference between W and We that occurs due to this effect is represented as .DELTA.W1, which is handled as a value of W when the gate-to-source transistor gain begins to become an effective value greater than zero;(b) the cross-sectional shape of a portion extending from the field oxide film to the gate oxide film differs depending on whether W is small or large; a difference between W and We that occurs due to this effect is represented as .DELTA.W2, which is handled as a function that increases as W becomes smaller in a region where W is smaller than a certain value; and(c) when the channel width is smaller than the width of the active regions on the source and drain sides and W is also smaller than a certain value, the corners on the source and drain sides are rounded due to the limitations of lithography as seen in a planar view; a difference between W and We that occurs due to this effect is represented as .DELTA.W3, which is handled as a function that increases as W becomes smaller in a region where W is smaller than a certain value, and increases as L become smaller in a region where the gate electrode length L in a direction orthogonal to the channel width direction is smaller than a certain value.