Tunnel Field-Effect Transistors for Analog/Mixed-Signal System-on-Chip Applications

In this paper, the analog performance is reported for the first time for a double-gate (DG) n-type tunnel field-effect transistor (n-TFET) with a relatively small body thickness (10 nm), which shows good drain current saturation. The device parameters for analog applications, such as transconductance gm, transconductance-to-drive current ratio gm/ID, drain resistance RO, intrinsic gain, and unity-gain cutoff frequency fT, are studied for DG n-TFET, with the help of a device simulator, and compared with that for a similar DG n-MOSFET. Although gm is lower, gm/ID is found to be higher in TFET, except for small values of the gate overdrive voltage, indicating that a TFET can produce higher gain at the same power level than a MOSFET. An extremely high RO and, hence, a high intrinsic gain are also observed for a TFET as compared with that for a MOSFET. A complementary TFET amplifier is found to have more than one order of magnitude higher voltage gain than its MOS counterpart. It is also demonstrated that the drain resistance and, hence, the device gain significantly degrade for increasing body thickness of a TFET.