A New “Shift and Ratio” Method for MOSFET Channel-Length Extraction

A new “shift and ratio” (S&R) method for extracting MOSFET channel length is presented. In this method, channel mobility can be any function of gate voltage, and high source-drain resistance does not affect extraction results. It is shown to yield more accurate and consistent channel lengths for deep-submicrometer CMOS devices at room and low temperatures. It is also found that, for both nFET and pFET, the source-drain resistance is essentially independent of temperature from 300 to 77 K. © 1992 IEEE