In-Situ Techniques for In-Field Sensing of NBTI Degradation in an SRAM Register File

📋 论文概要

本文提出一种原位传感技术，用于在SRAM寄存器文件中直接测量PMOS晶体管的阈值电压退化，从而感知负偏置温度不稳定性（NBTI）老化效应。该技术能够在现场工作，并对温度和电压变化具有鲁棒性，为动态可靠性管理（DRM）提供基础。

💡 主要创新点

• 提出一种直接在SRAM位单元中感知PMOS阈值电压的原位技术，无需额外测试结构。
• 该技术能够在现场（in-field）工作，且对温度和电压变化具有鲁棒性，适用于实际运行环境。
• 为动态可靠性管理（DRM）提供了关键的老化感知能力，可支持自适应补偿或降频等策略。

🏷 关键词

📄 原文摘要

SRAM register files have sensitive circuitry and often operate with high switching activity and at high temperature. This makes them particularly vulnerable to aging by negative-bias temperature instability (NBTI) degradation of their PMOS devices. We propose a technique to sense this aging degradation; it is an in-situ technique sensing the threshold voltage (Vt) of PMOSs directly in bitcells, and can operate in-field, thanks to the ability to sense Vt robustly across temperature and voltage variations. This technique can be foundational for several dynamic reliability management (DRM) approaches, including: 1) sensing Vt values periodically (e.g., every several months) for evaluating the amount and the rate of NBTI degradation; 2) sensing Vt differences between two PMOSs in a bitcell to determine their strength skew and to estimate the minimum functional voltage (VMIN) degradation; and, 3) using the skew

👥 作者与机构

Teng Yang, Doyun Kim, Peter R. Kinget, Mingoo Seok

Columbia University, New York, NY