A 28-nm 10.4-fJ/b Cryogenic embedded DRAM with 3T1C Gain Cell and MBIST at 4-Kelvin

Quantum error correction is essential for achieving large-scale quantum computing. Large-scale quantum state detection requires low-power embedded memory that can operate at 4K. Embedded Dynamic Random Access Memory is a strong candidate for cryogenic memory, offering high density and low power consumption. In this paper, we propose a cryogenic eDRAM using a 28nm CMOS process, which utilizes a 3T1C gain cell structure. Considering the short lifespan of the readout data, the refresh function of eDRAM is eliminated. Additionally, it integrates Memory Built-In Self-Test circuits for various testing purposes. We measured the performance of the eDRAM at 4K and achieved a read power of 4.9fJ/b and a write power of 15.9fJ/b. The median retention time reached 4.8ms, and the bandwidth reached 61.4Gb/s.