EXTRACTION OF CHANNEL LENGTH AND JUNCTION VOLTAGE IN N+/N/N+ OR N+/P/N+ POLYSILICON RESISTORS

A method for extraction of channel length and junction voltage of poly-Si resistors is presented. Direct extraction of channel length can be performed for n+/n/n+ resistors operating in the nonlinear I-V regime. However, poly-Si resistors may have channel doping opposite to that of the source/drain doping. For this case, a method is presented for extraction of the current-dependent voltage drop across the drain n+/p junction. Importantly, this junction voltage drop can be an appreciable fraction of the drain-to-source bias and thus is important for correct analysis of n+/p/n+ resistors.