Abstract

The ion-sensitive field effect transistor (ISFET) is a promising tool for detecting intermolecular interactions, including biochemical ones. Using the ISFET, it is possible to recognize various mechanisms of specifically adsorbed substances. In addition, ISFET can be integrated with CMOS technology, which opens up new prospects for creating intelligent micro- and nanosystems. In this study, the influence of the design and technological parameters of the ISFET on charge sensitivity is investigated using numerical simulation. Two types of the ISFET design based on a completely depleted floating-gate SOI structure are presented. The designs differ by the way of forming the liquid medium–gate contact. The analytical dependences of the charge sensitivity of the ISFET, which make it possible to analyze the ISFET sensitivity, are obtained. It is shown that the limiting sensitivity is achievable on a composite nanowire structure with submicron dimensions. The sensitivity of the considered ISFET design with the characteristic size of 1.2 µm when an analyte is adsorbed is about 50 effective electron charges. The ISFET designed with submicron physical dimensions (wire width of 10 nm and wire length of 100 nm) has the sensitivity of 1 to 2 effective electron charges.

中文翻译：

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基于离子敏感纳米线场效应晶体管的生物传感器，采用与浮栅的最小接触

摘要

离子敏感场效应晶体管（ISFET）是检测分子间相互作用（包括生化相互作用）的有前途的工具。使用ISFET，可以识别特定吸附物质的各种机制。此外，ISFET可以与CMOS技术集成在一起，这为创建智能微系统和纳米系统开辟了新的前景。在这项研究中，使用数值模拟研究了ISFET的设计和工艺参数对电荷敏感性的影响。提出了两种基于完全耗尽的浮栅SOI结构的ISFET设计。设计的不同之处在于形成液体介质-门接触的方式。获得了对ISFET的电荷灵敏度的分析依赖性，这使得可以分析ISFET灵敏度。结果表明，具有亚微米尺寸的复合纳米线结构可以实现极限灵敏度。吸附分析物时，特征尺寸为1.2 µm的ISFET设计的灵敏度约为50个有效电子电荷。具有亚微米物理尺寸（线宽为10 nm，线长为100 nm）设计的ISFET具有1至2个有效电子电荷的灵敏度。