Double gate movable body Micro-Electro-Mechanical FET as hysteretic switch: Application to data transmission systems

This paper reports on the fabrication, experimental characterization and data transmission application of a double-gate movable body FET. As its name suggests, the proposed movable-body Micro-Electro-Mechanical FET (MB-MEMFET) is a hybrid MEMS-semiconductor device that, in contrast with previously reported Suspended-Gate MOSFET, has a movable body separated by nano-size air gaps from two lateral fixed gates. We report here on the unique abrupt hysteretic characteristic of MB-MEMFET, which for our design offer reproducibility after intense cycling and, due to double gate architecture, a multi-level tunable hysteresis. Based on the I_D-V_G hysteretic behavior of the new hybrid device we report for the first time a FSK circuit exploiting oscillation at two selectable frequencies (26 kHz and 14 kHz) used to transmit numerical data, which demonstrates the potential of the MB-MEMFET for applications in data transmission systems.

I. Introduction

The combination of mechanically movable structures and semiconductor can result in new hybrid devices, such as Resonant Gate and Suspended-Gate MOSFET [1], [2], Nano-Electro-Mechanical FET [3] or Movable Body FET [4]. In general, three main categories of applications have been reported for these devices: (i) MEM/NEM resonators, (ii) abrupt switches for low power logic and (iii) NEM/MEM memory. It is also worth noting that there is an increased need for robust CMOS-compatible fabrication methods for the hybrid MEM/semiconductor devices in order to exploit them in circuit applications. Very recently Suspended-Gate MOSFET has been proposed for the measurement of nano-displacement using a CMOS-compatible process [5].