NBTI tolerant 4T double-gate SRAM design

In this paper, we propose 4T FinFET SRAM cells which are robust against NBTI effect. The cells, which only use NMOS or PMOS transistors in their structures, are called 4TLLFBNO and 4TDLFBPO, respectively. The simulation results at iso-area design reveal that 4TLLFBNO has the highest read current and 4TDLFBPO has the least power consumption among different cells. Both cells are expected to be robust for at least 3 years against the NBTI degradation considering the read and hold SNMs. Read current is also not degraded considerably in comparison with previous cells. The cells have good write SNM and write time and outperform the pervious cells in terms of the maximum number of cells per column without degrading by NBTI effect.