Ge Chang, Chen Yuezhong, Yu Daolong, Liu Zhixia, Xu Ji
The Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
School of Electronic and Information Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Sensors (Basel). 2024 Oct 21;24(20):6764. doi: 10.3390/s24206764.
As one of the most promising electronic devices in the post-Moore era, nanoscale vacuum field emission transistors (VFETs) have garnered significant attention due to their unique electron transport mechanism featuring ballistic transport within vacuum channels. Existing research on these nanoscale vacuum channel devices has primarily focused on structural design for logic circuits. Studies exploring their application potential in other vital fields, such as sensors based on VFET, are more limited. In this study, for the first time, the design of a vacuum field emission transistor (VFET) coupled with a piezoelectric microelectromechanical (MEMS) sensing unit is proposed as the artificial mechanoreceptor for sensing purposes. With a negative threshold voltage similar to an N-channel depletion-mode metal oxide silicon field effect transistor, the proposed VFET has its continuous current tuned by the piezoelectric potential generated by the sensing unit, amplifying the magnitude of signals resulting from electromechanical coupling. Simulations have been conducted to validate the feasibility of such a configuration. As indictable from the simulation results, the proposed piezoelectric VFET exhibits high sensitivity and an electrically adjustable measurement range. Compared to the traditional combination of piezoelectric MEMS sensors and solid-state field effect transistors (FETs), the piezoelectric VFET design has a significantly reduced power consumption thanks to its continuous current that is orders of magnitude smaller. These findings reveal the immense potential of piezoelectric VFET in sensing applications, building up the basis for using VFETs for simple, effective, and low-power pre-amplification of piezoelectric MEMS sensors and broadening the application scope of VFET in general.
作为后摩尔时代最具潜力的电子器件之一，纳米级真空场发射晶体管（VFET）因其独特的电子传输机制（在真空通道内实现弹道传输）而备受关注。目前对这些纳米级真空通道器件的研究主要集中在逻辑电路的结构设计上。探索其在其他重要领域应用潜力的研究，如基于VFET的传感器，则较为有限。在本研究中，首次提出了一种将真空场发射晶体管（VFET）与压电微机电系统（MEMS）传感单元相结合的设计，作为用于传感目的的人工机械感受器。所提出的VFET具有类似于N沟道耗尽型金属氧化物硅场效应晶体管的负阈值电压，其连续电流由传感单元产生的压电势调节，放大了机电耦合产生的信号幅度。已进行模拟以验证这种配置的可行性。从模拟结果可以看出，所提出的压电VFET具有高灵敏度和电可调测量范围。与传统的压电MEMS传感器和固态场效应晶体管（FET）组合相比，压电VFET设计由于其连续电流小几个数量级，功耗显著降低。这些发现揭示了压电VFET在传感应用中的巨大潜力，为使用VFET对压电MEMS传感器进行简单、有效和低功耗的前置放大奠定了基础，并拓宽了VFET的总体应用范围。
