Abstract
The dopingless tunneling FET (DLTFET) has attracted more and more attention due to the reduction of process complexity comparing to traditional TFET with heavy doping source and drain regions. But the on-state current of conventional DLTFET is lower because its on-state current is only determined by point tunneling (PT) between source and channel. In this work, a new dual-gate DLTFET based on line tunneling (LT) is designed and studied by Sentaurus TCAD simulation tool. The on-state current and subthreshold swing (SS) of DLTFET are greatly improved by skillfully designing back gate engineering and bias. Applying this novel design, the line tunneling is created from channel bottom to channel top, which dramatically enhances tunneling area and tunneling current. So the on-state current of LT_DLTFET consists of point tunneling between source and channel as well as line tunneling in channel region. Comparing to the traditional PT_DLTFET based on Ge, the simulation results reveal that the on-state current of LT_DLTFET based on Ge is increased to 14.8μA/μm from 6.5μA/μm at Vg=1V and Vd=0.5V, and the average SS and minimum SS are decreased to 22.9mV/dec and 6.5mV/dec from 33.9 mV/dec and 9.5mV/dec, respectively. The LT_DLTFET is also proper to both Si and III-V materials. This design greatly promotes the application potential of DLTFET.
Highlights
For LT_DLTFET, the transfer curve has a distortion when gate voltage (Vg) is increased to about 0.3V, this is due to the fact line tunneling starts to dominate the drain current when Vg reaches to 0.3V, whereas, the only point tunneling governs drain current for PT_DLTFET.22
Because the point tunneling generation rate is larger than that line tunneling generation rate at the condition of larger gate voltage, the increasing of tunneling current in LT_DLTFET is not obvious when gate voltage is larger than 1V
On the basis of conventional dual-gate structure, by adjusting the back gate engineering including work function and bias keeping other device parameter unchanged, the line tunneling is created in the aligned channel region between top gate and back gate
Summary
The size of metal oxide semiconductor field-effect transistor (MOSFET) is reduced to nanometer level so that extraordinary improvements in chip density, switching speed and operating power can be achieved. But the aggressive scaling-down of conventional MOSFETs has caused some reliability problems such as hot electron effect, drain induced barrier lowering (DIBL), high off-state leakage current, etc. Besides, the subthreshold swing of MOSFET is always larger than 60 mV/dec at room temperature, which degrades the switching ratio of on-state current and off-state current and increases difficulty in further reducing of supply voltage. the nanoscale MOSFETs cannot meet the need for the low power applications, which promotes the exploration of the novel low power devices which can be the substitute for MOSFET.In recent years, tunneling FET (TFET) has become a potential candidate for low power devices due to low subthreshold swing and low off-state leakage current. The main conduction mechanism of TFET is band to band tunneling (BTBT) instead of hot electron emission, which breaks the limitation of SS larger 60mV/dec.. The size of metal oxide semiconductor field-effect transistor (MOSFET) is reduced to nanometer level so that extraordinary improvements in chip density, switching speed and operating power can be achieved.. The aggressive scaling-down of conventional MOSFETs has caused some reliability problems such as hot electron effect, drain induced barrier lowering (DIBL), high off-state leakage current, etc.. The subthreshold swing of MOSFET is always larger than 60 mV/dec at room temperature, which degrades the switching ratio of on-state current and off-state current and increases difficulty in further reducing of supply voltage.. In recent years, tunneling FET (TFET) has become a potential candidate for low power devices due to low subthreshold swing and low off-state leakage current.. The main conduction mechanism of TFET is band to band tunneling (BTBT) instead of hot electron emission, which breaks the limitation of SS larger 60mV/dec.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
