基于有源屏蔽层的高精度电阻检测电路设计  

Design of a High-Precision Resistance Detection Circuit Based on the Active Shield

作　　者：叶茂 姜晓文 李尧 王秋玮 孔令威 赵毅强 Ye Mao;Jiang Xiaowen;Li Yao;Wang Qiuwei;Kong Lingwei;Zhao Yiqiang(School of Microelectronics,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology,Tianjin 300072,China)

机构地区：[1]天津大学微电子学院,天津300072 [2]天津市成像与感知微电子技术重点实验室,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2023年第8期807-814,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(61832018).

摘　　要：以聚焦离子束攻击和微探针攻击为主的侵入式物理攻击对芯片信息安全造成了严重威胁,有源屏蔽层作为安全芯片抵御侵入式物理攻击的第1道防线,由金属屏蔽层和完整性检测电路组成.金属屏蔽层用于遮盖安全芯片的关键模块及连接关系,完整性检测电路用于检测金属屏蔽层是否遭受攻击,二者相互配合来达到保护芯片内部敏感信息的目的.针对数字检测电路无法对重布线攻击进行检测的问题,基于GSMC 130 nm 1.5V 4P7M工艺设计了用于检测大面积金属屏蔽层固有电阻变化的电阻检测电路.该电路采用全差分处理架构提高了电阻检测精度,消除了温度漂移误差,同时实现了较低的功耗.基于特定的金属屏蔽层布线方案设计了电阻-电压转换电路,将金属屏蔽层固有电阻变化量转换为电压变化量,并设计了Delta-Sigma调制器和数字处理电路等,对电压变化量进行采样、量化、编码与比较.该电路实现了对包括重布线攻击在内的各类正面侵入式物理攻击的有效检测,提升了有源屏蔽层的防护能力.后仿真结果表明,该电路能对5 mm×5 mm的大面积金属屏蔽层进行电阻检测,能准确识别75 kΩ的金属屏蔽层电阻上发生的低至4Ω的微小变化,并产生高电平报警信号对芯片关键信息进行销毁;电路工作在-40~105℃温度范围内,检测周期为12 ms,检测周期内电路功耗为24.48μW,整体版图面积为370μm×135μm.Intrusive physical attacks,mainly the focused ion beam and microprobe attacks,pose a serious threat to chip information security.The active shield as the first line of defense for security chips against intrusive physical attacks consists of a metal shield and an integrity detection circuit.The metal shield covers the key modules and connections of the security chip,the integrity detection circuit detects the attack on the metal shield,and the two synergisti-cally work to protect the sensitive information inside the chip.However,the digital detection circuit cannot detect a rewiring attack.To address this issue,a resistance detection circuit was designed based on the GMSC 130 nm 1.5 V 4P7M process for detecting the inherent resistance change of a large-area metal shield.The circuit adopted a fully dif-ferential processing architecture to improve the resistance detection accuracy and eliminate temperature drift errors with lower power consumption.Based on the specific metal shield wiring scheme,a resistance-voltage conversion circuit was designed to convert the inherent resistance variation of the metal shield into voltage variation,and a Delta-Sigma modulator and a digital processing circuit were designed to sample,quantify,encode,and compare the voltage variations.The circuit can effectively detect various frontal intrusive physical attacks,including rewiring attacks,and improve the active shield protection capability.The post-simulation results show that the circuit can per-form resistance detection for a large-area metal shield of 5mm×5mm,accurately identifying even minimal changes as low as 4Ωoccurring on a 75kΩmetal shield resistance and generating a high-level alarm signal to destroy critical information on the chip.The circuit works in the temperature range of-40-105℃,with a detection period of 12 ms,a circuit power consumption of 24.48μW during the detection,and a layout area of 370μm×135μm.

关 键 词：侵入式物理攻击 有源屏蔽层 电阻检测 高精度 

分 类 号：TN492[电子电信—微电子学与固体电子学]