Performance Investigation of GaSb/Si Heterojunction based Gate Underlap and Overlap Vertical TFET Biosensor

The present paper estimates the performance of vertically developed double gate GaSb/Si tunnel field effect transistor (V-DGTFET) biosensor with source pocket. A commercially accessible tool, Silvaco-TCAD, is exploited for carrying simulations of V-DGTFET. The device’s novelty is deploying a material with a small bandgap, namely GaSb, in the source region to improve the carrier tunneling in sourcechannel (GaSb-Si) heterojunction. Further, the present work has analyzed the performance on half gate underlap and half gate overlap V-DGTFET based label-free biosensor. The performance of V-DGTFET biosensor corresponding to various biomolecules such as APTES with κ=3.57, bacteriophage-T7 with κ=6.4, apomyoglobin with κ =8.1 and gelatin with κ=12 is investigated with reference to energy band diagram, potential profile, electric field and drain characteristics. Furthermore, by considering the different values of dielectric constants from 1 to 12, the present paper computed the figure of merits (FOMs) essentially linearity and sensitivity. The results demonstrated that neutral biomolecules with higher dielectric constant values showed higher sensitivity compared with other biomolecules. Moreover, it is estimated that gelatin has to drain current sensitivity of 5.6×105, which is 13%, 20%, and 41% more in comparison to apomyoglobin (κ =8.1), bacteriophage-T7 (κ=6.4), and APTES (κ =3.57) sensitivity at 15 nm cavity length.

本研究针对带有源极口袋结构的垂直型双栅GaSb/Si隧道场效应晶体管（V-DGTFET）生物传感器的性能展开评估。本研究采用商用仿真工具Silvaco-TCAD开展V-DGTFET的仿真分析。该器件的创新之处在于在源极区域引入窄带隙材料GaSb，以优化源极-沟道（GaSb-Si）异质结处的载流子隧穿过程。此外，本研究针对半栅源极欠叠与半栅源极过叠结构的V-DGTFET型无标记生物传感器开展性能分析。本研究针对搭载多种生物分子（介电常数κ分别为3.57的APTES、6.4的T7噬菌体、8.1的肌红蛋白以及12的明胶）的V-DGTFET生物传感器，从能带图、电势分布、电场分布以及漏极特性等维度展开性能表征。此外，本研究通过设置1至12区间内的不同介电常数，计算得到该传感器的品质因数（FOMs），主要包括线性度与灵敏度两项核心指标。仿真结果表明，介电常数更高的中性生物分子相较其他生物分子具备更优异的传感灵敏度。此外，在腔长为15 nm的工况下，明胶的漏极电流灵敏度可达5.6×10^5，较介电常数为8.1的肌红蛋白、6.4的T7噬菌体以及3.57的APTES分别提升13%、20%与41%。