PHYSICALLY-BASED METHOD FOR MEASURING THE THRESHOLD VOLTAGE OF MOSFETS

A physically-based technique for measuring the threshold voltage of small geometry MOSFETs is presented. The new method, called the quasi-constant current (QCC) method, is based on the drain current equation in the sub-threshold region. It defines the threshold voltage as the gate voltage required for surface band-bending of 2-phi-F. Compared with some other commonly used methods, this technique has the advantages of better fitting accuracy in the sub-threshold region, of extracting the threshold voltage, V(TH), with a unique value based on a physical definition of the surface band-bending, and of being suitable for MOS devices over a wide range of voltage biases, device dimensions, and temperatures.