Analysis of the effect of the gate oxide breakdown on SRAM stability

Abstract

We have investigated the effects of oxide soft breakdown (SBD) on the stability of CMOS 6T SRAM cells. Gate-to-diffusion leakage currents of 20-50jiA at the n-FET source can result in a 50% reduction of noise margin. Breakdown at other locations in the cell may be less deleterious depending on rc-FET width. This approach gives targets for tolerable values of leakage caused by gate oxide breakdown. © 2002 Elsevier Science Ltd. All rights reserved.