A new method to determine MOSFET channel length

A new method is proposed to electrically determine MOS transistor channel length with both accuracy and convenience. Based on the linear region relationship between effective channel length L eff and channel resistance R chan of an MOS transistor, this method determines L eff by applying relatively large but constant gate voltage to eliminate threshold voltage determination and takes into account external resistance. Comparison of this method with SEM measurement shows very good agreement (within ±0.1 µm resolution limit of our SEM technique).