Experimental N-style two-transistor eDRAM in logic CMOS technology

In this work, we demonstrate an experimental eDRAM utilizing logic-compatible N-style 2T gain cell on 130 nm CMOS technology. The memory bit-cell consists of a high-V_TH write NMOS and a standard-V_TH read NMOS. Combination of a low off-leakage device for write and a high mobility device for read provides much improved retention time and read performance in a compact bit area. The embedded macro operates with 32-kbit density, SRAM-like I/O interface and self-timed 128-row refresh. Measured retention time in typical 32-kbit dies at 1.2 V and room temperature exhibits an average of 2.1 ms.