TMD-TCAM: Transition Metal Dichalcogenide Ternary Content Addressable Memory Enables Massive Parallel Data Search
Ternary content-addressable memory (TCAM) is specialized hardware for in-memory search and pattern-matching for data-intensive applications. However, challenges remain in achieving TCAMs with high search capacity, good area- and energy-efficiency. In this work, the researchers integrate two-dimensional (2D) MoS2 transistors with resistive random-access memories (RRAMs) into 2-transistor-2-resistor (2T2R) TCAM cells for the first time. The MoS2 transistors have very low leakage current and can program the RRAMs with exceptionally robust current control, enabling very large number of bits for parallel search. These TCAM cells show remarkably large resistance ratio (R-ratio) between match and mismatch states, up to 8.5×105. This R-ratio is comparable to that of commercial TCAMs using static random-access memories (SRAMs), with the key advantage that the 2T2R TCAMs use far fewer transistors and have zero stand-by power due to RRAM’s non-volatility. These results also represent a key application of 2D transistors, taking advantage of their high performance yet low leakage.