New method to determine effective channel widths of MOS transistors for VLSI device design

A resistive method for determining the effective channel widths of MOS transistors is presented. In this method, the series resistance is determined using the channel-length characterization method. A practical approximation is used to calculate the series resistance for transistors with different channel widths. The test structure for this method consists of two sets of transistors: one set contains transistors with different channel lengths and the same channel width, and the other set contains transistors with different channel widths and the same channel length. Experimental results show that the this method can be used with good accuracy when the series resistance is comparable to the channel resistance. The method is suitable for test structures with transistor channel-length in the submicrometer range.