Key issues and techniques for characterizing time-dependent device-to-device variation of SRAM

Discreteness of aging-induced charges causes a Time-dependent Device-to-Device Variation (TDDV) and SRAM is vulnerable to it. This work analyses the shortcomings of existing methods for SRAM application and propose a new technique for its characterization. The key issues addressed include the SRAM-relevant sensing Vg, measurement speed, capturing the maximum degradation, separating device-to-device variation from within-device fluctuation, sampling rate, time window, and test device numbers.