As an add-on device option for the ultra-low power CMOS technology, the double-gated vertical-channel Tunnel Field-Effect Transistors (TFETs) of different source configurations are comparatively studied from the perspectives of fabrication and current drivability. While the top-source design where the source of the device is placed on the top of the fin makes the fabrication and source engineering much easier, it is more susceptible to parasitic resistance issue. The bottom-source design is difficult to engineer the tunneling barrier and may require a special replacement technique. Examples of the schemes to engineer the tunneling barrier for the bottom-source TFET are suggested. A TCAD simulation study on the bottom-source devices shows that both the parasitic resistance of source region and the current enhancement mechanism by field coupling need be carefully considered in designing the source.

A novel tunneling field-effect transistor (TFET) featuring the sigma-shape embedded SiGe sources and recessed channel is proposed. The gate facing the source effectively focuses the E-field at the tip of the source and eliminates the gradual turn-on issue of planar TFETs. The fabrication scheme modified from the state-of-the-art 45 nm/32 nm CMOS technology flows provides a unique benefit in the co-integrability and the control of ID-VGS characteristics. The feasibility is verified with TCAD process simulation of the device with 14 nm of the gate dimension. The device simulation shows 5-order change in the drain current with a gate bias change less than 300 mV.

In a patch-based super-resolution algorithm, a low-resolution patch is influenced by surrounding patches due to blurring. We propose to remove this boundary effect by subtracting the blur from the surrounding high-resolution patches, which enables more accurate sparse representation. We demonstrate improved performance through experimentation. The proposed algorithm can be applied to most of patch-based super-resolution algorithms to achieve additional improvement.

Although the Tunnel Field-Effect Transistor (TFET) is a promising device for ultra-low power CMOS technology due to the ability to reduce power supply voltage and very small off-current, there have been few reports on the control of VT for TFETs. Unfortunately, the TFET needs a different technique to adjust VT than the MOSFET by channel doping because most of TFETs are fabricated on SOI substrates. In this paper, we propose a technique to control VT of the TFET by putting an additional VT-control doping region (VDR) between source and channel. We examine how much VT is changed by doping concentration of VDR. The change of doping concentration modulates VT because it changes the semiconductor work function difference, ψs,channel-ψs,source, at off-state. Also, the effect of the size of VDR is investigated. The region can be confined to the silicon surface because most of tunneling occurs at the surface. At the same time, we study the optimum width of this region while considering the mobility degradation by doping. Finally, the effect of the SOI thickness on the VDR adjusted VT of TFET is also investigated.