Single Device MOSFET Series Resistance Extraction Methods: Comparison Between Newer and Older

Older and newer methods for extracting MOSFET source/drain series resistance are compared and discussed. Both methods use a single device for extraction, and tries to exploit internal bias modulation induced by varying applied drain voltage. It will be shown that the older method does not properly work in its original form, since it is strongly affected by only a slight change of mobility caused by applied biases, especially by weak velocity saturation. The newer method, which overcomes this problem by taking into account the dependence of mobility on both gate and drain biases, is used to graphically illustrate how the mobility change affects the older one.