Computer analysis of the double-diffused MOS transistors and integrated circuits

The effective channel length of an MOS transistor can be made narrow by using double-diffusion similar to a bipolar transistor as shown by Tarui et al and Gauge et al. The reduction of the channel surface concentration toward the drain junction decreases or reverses the threshold voltage into the depletion mode, thus making the channel conductance higher than conventional transistors of the same channel length. Due to the grading of the channel surface concentration, the analysis of such a structure cannot be made as readily as conventional uniform background transistor. An analysis of the characteristics was conducted with the aid of a digital computer.