A Monolithic 3D IGZO-RRAM-SRAM-integrated Architecture for Robust and Efficient Compute-in-memory Enabling Equivalent-Ideal Device Metrics

Compute-in-memory (CIM) based on various devices such as static random access memory (SRAM) and resistive random access memory (RRAM) and other emerging devices such as indium-gallium-zinc-oxide (IGZO) transistor, magnetoresistive RAM (MRAM), and ferroelectric RAM (FeRAM) has been explored for better performance and energy efficiency on neural networks applications. However, CIM based on a single-type device suffers a variety of non-ideal metrics to reach the simultaneous optimal accuracy, density, and energy efficiency. This work presents equivalent-ideal CIM (Eq-CIM), a monolithic 3D (M3D) IGZO-RRAM-SRAM integrated architecture for robust and efficient compute-in-memory enabling equivalent-ideal device metrics. To overcome the non-ideality (variation, endurance, temperature, etc.) of the single-type devices, system-technology co-optimization (STCO) is performed. This work highlights the non-ideality-aware functionality breakdown for robust high accuracy and simultaneous high density/efficiency, by utilizing 2T0C IGZO for temporal activation storage, RRAM for high-density weight storage, and SRAM for accurate CIM. Device-to-algorithm variation transfer is applied to analyze the system-level accuracy. We benchmark Eq-CIM architecture on CIFAR-10/ImageNet, with 5.06× storage density and 5.05×/2.45× area/energy efficiency compared with single-type-device-based CIM, and high robustness (<0.27