Enhancing FeCAP Arrays with Selector Devices
Investigating selector integration to suppress voltage disturbance in large-scale FeRAM/FeCAP arrays
Project Overview
This project studied polarization disturb in vertical FeCAP/FeRAM crossbar arrays and explored the use of nonlinear selector devices to mitigate sneak path currents and improve sense margin reliability. Circuit-level modeling and experimental validation demonstrated that integrating a metal–semiconductor–metal (MSM) selector with ferroelectric capacitors suppresses unwanted voltage drops during partial-bias schemes (VW/2, VW/3), thereby extending array endurance and reducing disturb failures
Key Features
⚡ Disturb Suppression: Up to 9× reduction in disturb after 10⁶ cycles under VW/2 inhibition
🔌 MSM Selector Integration: a-Si based MSM selector modeled and experimentally validated
📐 Sub-linear Voltage Division: Selector introduces nonlinear I–V response, protecting ferroelectric voltage during inhibit pulses
🖥️ Circuit-Level Validation: Compact selector model calibrated with measured MSM devices
Research Contributions
Proposed selector–capacitor stack (MSMFM) for FeCAP disturb mitigation
Built a compact Verilog-A model for MSM selector calibrated against experimental data
Demonstrated suppression of polarization loss in both VW/2 and VW/3 schemes through TCAD-informed circuit simulations
Fabricated and characterized integrated MSMFM stacks, confirming model predictions
Technical Achievements
Achieved stable polarization retention at 120 °C with MSM selector integration
Demonstrated sub-linear VFE–VAPP behavior enabling write–disturb separation
Validated selector-based disturb mitigation experimentally in large-array inhibition conditions
Advanced feasibility of high-density FeCAP arrays with integrated selector devices
Applications
High-density FeRAM/FeCAP crossbars with reduced disturb errors
Compute-in-memory (CIM) accelerators, requiring robust multi-cell operations
Low-power embedded NVM in AI, IoT, and security-critical systems
Impact and Recognition
This work demonstrated how nonlinear selector integration enables scalable, reliable ferroelectric arrays by reducing sneak paths and improving disturb resilience. The project was published in the VLSI Technology & Circuits Symposium 2025, highlighting its significance for next-generation 3D FeRAM and CIM systems
