ELECTRICAL CHARACTERISTICS OF A DSA MOS-TRANSISTOR WITH A FINE-STRUCTURE

Fabrication technologies and· electrical characteristics of a diffusion self-aligned MOS transistor (DSA MOST) or a double-diffused MOS transistor (DMOST) are discussed in comparison with a conventionalshort -channel-MOS transistor as a fundamental device for a VLSI. The symmetrical DSA MOS LSI with enhancement depletion configurations requires six photolithographic steps and the number of the steps is the same as that of an NMOS LSI with small physical dimensions. The only difference is the step orders of the enhancement channel dopingin these devices. The lowering effects of the threshold voltage and the source drain breakdown voltage are smaller in the DSA MOST than in the conventional MOS transistor. The drain current 1D of the symmetrical DSA MOS transistor is, respectively, 1.13. (in the nonsaturation region) and 1.33 (in the saturation region) times larger than that of the conventional, short-channel NMOS transistor at the effective gate voltage of 3.0 V. The improvement of the short-channel effect, the current voltage characteristics, and the power-delay product are obtained by the scaling of the DSA MOS transistor. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.