High-density SOT-MRAM technology and design specifications for the embedded domain at 5nm node
Mohit Gupta, Manu Perumkunnil, Kévin Garello, Siddharth Rao, Faisal Mohd-Yasin, Gouri Sankar Kar, A. Furnémont
Abstract
Spin Orbit Torque (SOT) magnetic random-access memory (MRAM) offers the possibility to realize ultra-high-speed Non-Volatile memory technology without endurance issues that plague its more mature counterpart, STT-MRAM, but at cost of density. Based on our SOT-MRAM technology data, we explore different bit-cell architectures through extensive Design Technology Co-optimization (DTCO) to evaluate the most pareto-optimum solutions for High-Density [HD] and High-Performance [HP] and we design full SOT-MRAM macro for embedded domain. Our design-technology specifications projections show that using Resistance-Area (RA) product of 4 Ω.μm2, MTJ diameter of 32nm, SOT trackwidth of 35nm and SOT efficiency θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SHE</sub> ≥1.4 enables: i) a HP SOT-MRAM macro with operating frequency (RD/WR) ≈1.05/0.71GHz at the 5nm process node and a 40% bit-cell area reduction compared to the 122 SRAM, ii) a HD SOT-MRAM macro with operating frequency (RD/WR) ≈ 1.1/0.45GHz and 37.5% area reduction compared to the 111 SRAM. Our analysis reveals that the bit line parasitic will be a limiting factor to SOT-MRAM performance at advanced nodes.