A 1.1V, 667MHz random cycle, asymmetric 2T gain cell embedded DRAM with a 99.9 percentile retention time of 110µsec

Abstract

A logic compatible embedded DRAM test macro fabricated in a 65nm LP CMOS process has a 512 cells-per-BL array architecture and achieves a random access frequency and latency of 667MHz and 1.65nsec, respectively at 1.1V, 85°C. The refresh period for a 99.9% bit yield was 110μsec. Key features include an asymmetric 2T gain cell, a pseudo-PMOS diode based current sensing scheme, a half swing write BL driver, and a stepped write WL technique.