Design and analysis of a self-repairing SRAM with on-chip monitor and compensation circuitry

In an SRAM array, the systematic inter-die and the random within-die variations in process parameters cause significant number of parametric failures, to degrade process yield in the nanometer technology regime. In this paper, we investigate the interaction between the inter-die and intra-die V t variations on SRAM read and write failures. To improve robustness of SRAM cell, we propose a closed-loop compensation scheme using on-chip monitors that directly sense the global read stability and writability of the cell directly. Computer simulations based on 45nm PD/SOI technology demonstrate the viability and effectiveness of the scheme in SRAM yield enhancement. © 2008 IEEE.