29.8 SHARC: Self-Healing Analog with RRAM and CNFETs
29.8 SHARC: Self-Healing Analog with RRAM and CNFETs
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DOI：
10.1109/isscc.2019.8662377
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Aya G. Amer;R. Ho;G. Hills;A. Chandrakasan;M. Shulaker
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文献类型：
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作者：
Aya G. Amer;R. Ho;G. Hills;A. Chandrakasan;M. Shulaker
碳纳米管（CNT）场效应晶体管（CNFET）是一种有前途的新兴节能电子技术（图29.8.1）。尽管有这样的前景，但CNT受到实质性的固有缺陷的影响; CNT的每个集合体包括一定百分比的金属CNT（m-CNT）。m-CNT导致CNFET源极和漏极之间导电短路，从而导致过度泄漏和电路功能退化（可能不正确）（图29.8.1）。已经开发了几种技术来去除大部分m-CNT（今天没有技术去除100%的m-CNT）。虽然这些技术实现了第一个数字CNFET电路，但由于m-CNT，仍然不可能实现大规模CNFET模拟或混合信号CNFET电路。如图29.8.1所示，虽然数字逻辑门在存在一小部分m-CNT的情况下仍然可以正常工作（但对噪声的弹性降低）[1]，但模拟电路中的单个m-CNT可能导致灾难性故障（例如，降低放大器增益，导致电路块（例如ADC和DAC）的功能故障）1.本文提出了一种电路设计技术，自愈模拟与RRAM和CNFET（SHARC），利用非易失性电阻RAM（RRAM）的可编程性自动“自愈”模拟电路中存在的m-CNT。使用SHARC，我们通过实验证明了模拟CNFET电路对m-CNT的鲁棒性以及第一个混合信号CNFET子系统（4位DAC和SAR ADC;这些是迄今为止报道的最大的互补（CMOS）CNFET电路演示）。
Carbon nanotube (CNT) field-effect transistors (CNFETs) are a promising emerging technology for energy-efficient electronics (Fig. 29.8.1). Despite this promise, CNTs are subject to substantial inherent imperfections; every ensemble of CNTs includes some percentage of metallic CNTs (m-CNTs). m-CNTs result in conductive shorts between CNFET source and drain, resulting in excessive leakage and degraded (potentially incorrect) circuit functionality (Fig. 29.8.1). Several techniques have been developed to remove the majority of m-CNTs (no technique today removes 100% of m-CNTs). While these techniques enabled the first digital CNFET circuits, it is still not possible to realize large-scale CNFET analog or mixed-signal CNFET circuits due to m-CNTs. As shown in Fig. 29.8.1, while a digital logic gate can still function correctly in the presence of a small fraction of m-CNTs (but with degraded resilience to noise) [1], a single m-CNT in an analog circuit can result in catastrophic failure (e.g., degrading amplifier gain resulting in functional failure of circuit blocks such as ADCs and DACs)1. This paper presents a circuit design technique, Self-Healing Analog with RRAM and CNFETs (SHARC), that leverages the programmability of non-volatile resistive RAM (RRAM) to automatically “self-heal” analog circuits in the presence of m-CNTs. Using SHARC, we experimentally demonstrate analog CNFET circuits robust to m-CNTs as well as the first mixed-signals CNFET sub-system (4-bit DAC and SAR ADC; these are the largest reported complementary (CMOS) CNFET circuit demonstrations to-date).