In this paper, we propose and investigate a dielectric modulated (DM) GaAs_1−x Sb _x FinFET as a label-free biosensor. Raised source drain (RSD) architecture is employed in the proposed structure, resulting in a large surface to volume ratio, which provides more living space to the biomolecules. GaAs_1−x Sb _x is used as a channel material, which bestows higher carrier mobility and consequently offers better sensitivity than previously reported FET-based biosensors. In our proposed RSD GaAs_1−x Sb _x FinFET, we have embedded a nanogap (∼5.5 nm thickness) cavity between the gate and the channel region at which biomolecules can reside in a dry environment. The presence of biomolecules (charged or neutral) in the embedded nanogap cavity of a DM biosensor could be identified by the change in various electrical parameters such as ON–OFF current ratio (CR), threshold voltage (V _th), transconductance, and intrinsic gain, etc, with the change in dielectric constant (K) of the cavity region. We found the maximum sensitivity corresponding to K = 12 is 48.91% and 26.31% for CR and V _th, respectively. The governing physics to observe the substantial changes due to the velocity overshoot, capacitive coupling, and DIBL is thoroughly explained. The analysis of how one cavity of the proposed biosensor works at a time is also investigated. In our work, we have also identified the impact of biomolecules which carry charges by including trap models in numerical TCAD simulations.

在本文中，我们提出并研究了一种介电调制 (DM) GaAs _{1− x} Sb _x FinFET 作为无标记生物传感器。所提出的结构中采用了升高的源漏 (RSD) 架构，从而产生了较大的表面积与体积比，从而为生物分子提供了更多的生存空间。GaAs _{1− x} Sb _x用作通道材料，它提供更高的载流子迁移率，因此提供比以前报道的基于 FET 的生物传感器更好的灵敏度。在我们提出的 RSD GaAs _{1− x} Sb _x FinFET，我们在栅极和沟道区域之间嵌入了一个纳米间隙（约 5.5 nm 厚度）腔，生物分子可以在该腔内驻留干燥环境。生物分子在DM生物传感器的嵌入式纳米间隙腔中的存在（带电荷的或中性的）可以通过在各种电参数，例如ON-OFF电流比（CR），阈值电压（变化来识别V _日），跨导和本征增益等，随着腔区介电常数 ( K )的变化。我们发现对应于K = 12的最大灵敏度为 48.91% 和 26.31% CR 和V _th， 分别。彻底解释了观察由于速度超调、电容耦合和 DIBL 引起的实质性变化的控制物理学。还研究了所提出的生物传感器的一个腔如何一次工作的分析。在我们的工作中，我们还通过在数值 TCAD 模拟中包含陷阱模型，确定了携带电荷的生物分子的影响。