Heracles: A HfO2 Ferroelectric Capacitor Compact Model for Efficient Circuit Simulations

2024-10-10

arXiv.org

AI Summary

HfO₂-based ferroelectric capacitors (FeCaps) require circuit-level modeling beyond non-volatile memory applications, yet existing models lack physical fidelity, SPICE compatibility, and support for statistical variability and partial polarization switching. Method: This work proposes a physics-driven, SPICE-compatible compact model that uniquely integrates thermo-electric coupling, experimentally calibrated parasitic parameters, and statistical device variation—enabling accurate modeling of partial polarization reversal, Monte Carlo analysis, and design–technology co-optimization (DTCO). Contribution/Results: By precisely extracting and embedding parasitics and process-induced variations, the model achieves convergence in just 1.8 seconds for a 100-kb array simulation and faithfully reproduces critical partial-switching behavior in current-programming circuits. Compared to prior models, it significantly improves simulation accuracy, runtime efficiency, and process robustness—providing an EDA-embeddable, practical tool for early-stage FeCap circuit design and performance evaluation.

Technology Category

• Machine Learning: Hardware-aware ML
• Cognitive Modeling & Cognitive Systems: Neural Spike Coding
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories

Application Category

• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for incomplete, noisy, or partially observed Web-related graphs
• Security and Privacy: Large-scale security measurements

Abstract

The growing use of ferroelectric-based technology, extending beyond conventional memory storage applications, necessitates the development of compact models that can be easily integrated into circuit simulation environments. These models assist circuit designers in the design and the early assessment of the performance of their systems. The Heracles model is a physics-based compact model for circuit simulations in a SPICE environment for HfO2-based ferroelectric capacitors (FeCaps). The model has been calibrated based on experimental data obtained from HfO2-based FeCaps. A thermal model with an accurate description of the device parasitics is included to derive precise device characteristics based on first principles. The incorporation of statistical device data enables Monte Carlo analysis based on realistic distributions, thereby rendering the model particularly well-suited for design-technology co-optimization (DTCO). The model's efficacy is further demonstrated in circuit simulations using an integrated circuit with current programming, wherein partial switching of the ferroelectric polarization is observed. Finally, the model was benchmarked in an array simulation, reaching convergence in 1.8 s with an array size of 100 kb.

Problem

• Develop compact model for HfO2 ferroelectric capacitors.
• Enable efficient circuit simulations in SPICE environment.
• Support design-technology co-optimization with statistical data.

Innovation

• Physics-based compact model for HfO2 FeCaps
• Includes thermal model and device parasitics
• Enables Monte Carlo analysis for DTCO