HTOL SRAM Vmin shift considerations in scaled HKMG technologies

This paper examines the role of NBTI and PBTI on SRAM Vmin shifts during HTOL stressing and quantifies their impact on reliability lifetime projections in scaled high-k metal gate (HKMG) technologies. Correlation between measured HTOL SRAM Vmin shifts and transistor level parametrics is summarized on both 28nm poly-SiON and HKMG technologies. The paper concludes that the commonly used HTOL acceleration voltage of 1.4xVnom may be excessive in scaled HKMG technologies due to the larger role of PBTI in SRAMs.

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