Optimizing Radiation Hard by Design SRAM Cells

Various radiation hardened by design SRAM cells are explored for their size, electrical performance, and total ionizing dose (TID) immunity. TID experiments using Co-60 testing on 130- and 90-nm transistors and SRAM arrays show that SRAM cells using two-edge transistors, NMOS access transistors, and NMOS reverse-body-bias effectively mitigate TID in both generations. This work experimentally demonstrates that commercial foundry (optimally sized) SRAM cells can be used in radiation hardening by design if NMOS reverse-body bias is used for TID mitigation.