A highly reliable radiation hardened 8T SRAM cell design

In this paper, a new Radiation Hardened By Design (RHBD) 8T SRAM cell is proposed that can tolerate single event upset (SEU) in a radiation environment. According to the simulation results for 130 nm silicon-on-insulator (SOI) technology, the critical charge of the proposed 8T cell increases by 82.9% compared to the conventional 6T SRAM cell and by 62.5% compared to the other RHBD SRAM cell, the Soft-error-Tolerant-10T (ST-10T) cell. Pulsed laser testing was used for SEU sensitivity evaluation. Further, the energy threshold of the proposed cell increases by 122.3% and 90.8%, respectively, compared to the conventional 6T cell and the ST-10T cell. Moreover, the proposed cell has a lower leakage current, higher read current, and larger read static noise margin (RSNM) compared to the other two cells. The total ionizing dose (TID) effects on the proposed 8T SRAM cell were also studied, and the results show that the proposed cell is insensitive to TID.