A new approach to determine the effective channel length and the drain-and-source series resistance of miniaturized MOSFET's

A new decoupled C-V method is proposed to determine the intrinsic (effective) channel region and extrinsic overlap region for miniaturized MOSFET's. In this approach, a unique channel-length-independent extrinsic overlap region is extracted at a critical gate bias, so bias-independent effective channel lengths (L/sub eff/) are achieved. Furthermore, the two-dimensional (2D) charge sharing effect is separated from the effective channel region. Based on this L/sub eff/ and the associated bias-dependent channel mobility, /spl mu//sub eff/, the drain-and-source series resistance (R/sub DS/) can be derived from the I-V characteristics for each device individually. For the first time, the assumption or approximation for R/sub DS/ and /spl mu//sub eff/ can be avoided, thus the difficulties and controversy encountered in the conventional I-V method can be solved. The 2D charge sharing effect is incorporated into the bias-dependent R/sub DS/. This bias dependence is closely related to the drain/source doping profile and the channel dopant concentration. The proposed L/sub eff/ and R/sub DS/ extraction method has been verified by an analytical I-V model which shows excellent agreements with the measured I-V characteristics.<
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