Field-effect transistor (FET)-based biosensors with stacked gate oxides provide low leakage current and high sensitivity. However, an undesirable interfacial layer of silicate and silicon dioxide is formed in between the stacked oxides. In this paper, an underlap silicon-on-nothing FET-based biosensor with high-K gate oxide is presented for the detection of charged biomolecules, thereby removing the unwanted interfacial layer while preserving the sensitivity of the device. The study is based on a surface potential model for the proposed device, which is developed from Poisson’s equation by incorporating the dielectric and charge properties of the biomolecules. A threshold voltage model is then developed to examine the sensitivity of the device. The change in the device characteristics upon the accumulation of biomolecules is investigated to understand the impact of the biomolecules on the behavior and sensitivity of the device. The results show that the proposed device is highly sensitive to charged biomolecules, and that the charge of the biomolecules is more important than their dielectric properties for modulating the device characteristics. The results indicate that the proposed device has potential to be chosen as a new type of highly sensitive, nanosize, label-free biosensor with no unwanted interfacial layer. The analytical model is validated against two-dimensional (2-D) numerical simulation data obtained from ATLAS (SILVACO).

中文翻译：

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高K下重叠介电和电荷调制无硅FET生物传感器的分析模型

具有堆叠栅氧化物的基于场效应晶体管（FET）的生物传感器可提供低泄漏电流和高灵敏度。然而，在堆叠的氧化物之间形成了不期望的硅酸盐和二氧化硅的界面层。本文提出了一种具有高K值的无叠底场效应管FET生物传感器提出了一种用于检测带电生物分子的栅氧化层，从而去除了多余的界面层，同时保持了器件的灵敏度。这项研究基于所提出设备的表面电势模型，该模型是通过结合生物分子的介电和电荷特性从泊松方程发展而来的。然后建立阈值电压模型以检查设备的灵敏度。研究了生物分子积累后器件特性的变化，以了解生物分子对器件行为和灵敏度的影响。结果表明，所提出的装置对带电的生物分子高度敏感，并且生物分子的电荷比其介电特性对调节装置的特性更为重要。结果表明，所提出的装置有可能被选为新型的高灵敏度，纳米尺寸，无标签的生物传感器，并且没有不需要的界面层。根据从ATLAS（SILVACO）获得的二维（2-D）数值模拟数据对分析模型进行了验证。