Worst-Case Bit Line Coupling Backgrounds for Open Defects in SRAM Cells

In this paper, we present an evaluation of the impact of bit line (BL) coupling on the faulty behavior of an SRAM cell in the presence of specific data in the neighborhood cells. In a nutshell, we tackle the following problem: given a defective SRAM cell with parasitic coupling effects, where the parasitic effect is capacitive, determine specifically the influential open defects, the impact of neighborhood coupling data on the faulty cell, all stressful coupling background data and thus, quantify the magnitude of the worst-case coupling background (WCB) against other stressful coupling background (CB) for each defect. Our results show that for a read 0 operation, CB 00 is the most stressful, while for a read 1 operation, the CB 11 is the most stressful. The exact amount of stress depends both on the location of the defect and the amount of BL coupling.