Technical Session at IDEM: Foundry Monolithic 3D
We present the first foundry monolithic 3D (M3D) memory + logic circuits: full M3D memory arrays with tucked sense amplifiers (TSAs) driving digital logic. Achieved at SkyWater Foundry (90/130 nm, 200 mm wafers), our M3D process heterogeneously integrates Si CMOS, resistive RAM (RRAM), and carbon nanotube FETs (CNFETs) in the BEOL at ≤415 °C. The M3D design achieves 4× read bandwidth and 4× compute throughput at iso-latency and iso-footprint compared to a Si CMOS + RRAM baseline. This is enabled by (a) a robust BEOL-compatible process with CNFET + RRAM offering comparable performance and endurance to Si FET + RRAM, (b) ultra-dense vias at RRAM metal pitch, and (c) novel TSA-based 3D memory architectures. Our platform includes a complete M3D PDK, enabling further design innovations. This demonstration marks the first foundry-supported M3D memory + logic platform with practical integration of advanced device technologies.