Abstract
This paper investigates the impact of thermal stability relaxation in double-barrier magnetic tunnel junctions (DMTJs) for energy-efficient spin-transfer torque magnetic random access memories (STT-MRAMs) operating at the liquid nitrogen boiling point (77 K). Our study is carried out through a macrospin-based Verilog-A compact model of DMTJ, along with a 65 nm commercial process design kit (PDK) calibrated down to 77 K under silicon measurements. Comprehensive bitcell-level electrical characterization is used to estimate the energy/latency per operation and leakage power at the memory architecture-level. As a main result of our analysis, we show that energy-efficient small-to-large embedded memories can be obtained by significantly relaxing the non-volatility requirement of DMTJ devices at room temperature (i.e., by reducing the cross-section area), while maintaining the typical 10-years retention time at cryogenic temperatures. This makes DMTJ-based STT-MRAM operating at 77 K more energy-efficient than six-transistors static random-access memory (6T-SRAM) under both read and write accesses (−56% and −37% on average, respectively). Obtained results thus prove that DMTJ-based STT-MRAM with relaxed retention time is a promising alternative for the realization of reliable and energy-efficient embedded memories operating at cryogenic temperatures.
Original language | English |
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Article number | 108315 |
Journal | Solid-State Electronics |
Volume | 194 |
DOIs | |
State | Published - Aug 2022 |
Bibliographical note
Funding Information:The following grant information was disclosed by the authors: Polish Ministry of Science and Higher Education: 026/RID/2018/19.
Publisher Copyright:
© 2022 Elsevier Ltd
Keywords
- 77 K
- Cryogenic cache
- Cryogenic electronics
- Double-barrier magnetic tunnel junction (DMTJ)
- STT-MRAM
- Thermal stability relaxation