A new extraction algorithm for the metallurgical channel length of conventional and LDD MOSFET's

Abstract

A new extraction algorithm for the metallurgical channel length of conventional and LDD MOSFET's is presented, which is based on the well-known resistance method with performing a special technique to eliminate the uncertainty of the channel length as well as to reduce the influence of the parasitic source/drain resistance on threshold-voltage determination. In particular, the metallurgical channel length is determined from a wide range of gate-voltage-dependent effective channel length at an adequate gate overdrive, The 2-D numerical analysis clearly show that the adequate gate overdrive is strongly dependent on the dopant concentration in the source/drain region, Therefore, an analytic equation is derived to determine the adequate gale overdrive for various source/drain and channel doping, It shows that higher and lower gate overdrives are needed to accurately determine the metallurgical channel length of conventional and LDD MOSFET devices, respectively. It is the first time that we can give a Correct gate overdrive to extract L(met) not only for conventional devices but also for LDD MOS devices. Besides, the parasitic source/drain resistance call also he extracted using our new extraction algorithm.