학술논문

A 1-Mbit Fully Logic-Compatible 3T Gain-Cell Embedded DRAM in 16-nm FinFET
Document Type
Periodical
Source
IEEE Solid-State Circuits Letters IEEE Solid-State Circuits Lett. Solid-State Circuits Letters, IEEE. 3:110-113 2020
Subject
Components, Circuits, Devices and Systems
Computing and Processing
Random access memory
FinFETs
Temperature measurement
Leakage currents
Power demand
Voltage measurement
Embedded DRAM
gain cell (GC)
low voltage
retention time
SRAM
Language
ISSN
2573-9603
Abstract
Gain-cell embedded DRAM (GC-eDRAM) is a logic-compatible embedded memory alternative to SRAM, offering higher density, lower leakage power consumption, and an inherent two-ported functionality. However, increased leakage currents and process variations under technology scaling lead to a reduced data retention time (DRT), resulting in increased refresh power and reduced memory availability, currently limiting its implementation to planar 28-nm technologies and above. This letter presents the first gain-cell embedded DRAM (GC-eDRAM) in 16-nm FinFET technology, featuring a mixed- $V_{T}$ 3T gain-cell structure to minimize the storage node (SN) leakage. The implemented 1-Mbit 3T GC-eDRAM is fully logic-compatible and provides a $2\times $ smaller bitcell size compared to a 6T SRAM with similar design rules, offering the highest density logic-compatible memory cell in 16-nm technology. Measurement results demonstrate a 77- $\mu \text{s}$ DRT under a 600-mV $V_{\text {DD}}$ , which is over $10\times $ longer than previously reported GC-eDRAMs in 28-nm technologies. The memory was fully operational at temperatures spanning −40 °C to 125 °C and under a supply voltage as low as 450 mV, providing the lowest measured $V_{\text {DDmin}}$ and widest temperature range reported in the literature for GC-eDRAM.