The 2T Gain Cell based EDRAM in 28nm HKMG operating at Cryogenic Temperatures with more than 6s retention time at 4K has been accepted for the CICC-2021 under the Circuits for Machine Learning and cryo-CMOS Applications track.


Cryogenic memory is pivotal in building high performance digital systems, quantum and other superconducting computers. In this paper we demonstrate a 1kb-2T-Hybrid-Gain-cell-based EDRAM operating between 4K-300K with a peak FMax of 1.3GHz(at 4K). Due to the improved ON currents and Subthreshold Swing and reduced Leakage currents, we see more than 10^6 increase in the retention time, 1.7X more energy-efficiency and sub nW/kb array refresh power at 4K compared to 300K.