Elimination of half select disturb in 8T-SRAM by local injected electron asymmetric pass gate transistor

Abstract

8T-SRAM cell with asymmetric pass gate transistor by local electron injection is proposed to solve half select disturb. Two types of electron injection scheme: both side injection scheme and self-repair one side injection scheme are analyzed comprehensively for 65nm technology node 8T-SRAM cell and also for 6T-SRAM cell. This paper shows that in the 6T-SRAM with the local injected electrons the read speed degrades by as much as 6.3 times. In contrast, the proposed 8T-SRAM cell with the self-repair one side injection scheme is most suitable to solve the conflict of the half select disturb, write disturb and read speed. In the proposed 8T-SRAM, the disturb margin increases by 141% without write margin or read speed degradation. The proposed scheme has no process or area penalty compared with the standard CMOS-process 8T-SRAM.