Dual-Threshold Independent-Gate TFETs With Tri-side Tunneling And Their Optimizations

This paper presents a Dual-threshold Independent-Gate TFET with Tri-Side Tunneling(TSIG-TFET).By changing the structure of the device and picking up the appropriate source and drain material,the on-current of the device is significantly extended.When compare to the traditional Dual-Gate Tunneling Field Effect Transistor(DG-TFET),it shows that TS-IGTFET has strong competitiveness.In addition,independent gate devices with strong coupling between back and front gates can generate different logic by using different device threshold voltages,which can reduce the number of transistors used in circuits.The results show that the proposed low-threshold TS-IG-TFET has “OR” logic function,while high-threshold TS-IG-TFET has “AND” logic function.The main innovations of this paper are as follows.1)As the size of traditional MOSFET devices decreases,their performance is increasingly affected by short-channel effects and quantum effects.The proposed TFET device effectively solves the negative effects caused by short-channel effects and quantum effects.Its quantum effects based on band-to-band tunneling(BTBT)enable it to break through the 60 m V/dec limit.But at the same time,TFET devices also face their own problems,that is,the problem that the on-state current is too small.In order to meet the needs of practical application development,this article improves the traditional TFET device.First of all,in the structure,the traditional TFET device can only have one side of the inter-band tunneling,but this article will expand to three sides to the greatest extent.This change will greatly increase the tunneling area and thus increase the on-state current.2)Secondly,in terms of material selection,traditional TFET devices generally use silicon and germanium materials.This paper will analyze and compare the materials in detail.Finally,In As and Ga Sb are selected as the source and drain materials of the N-type TFET.In As Sb and Ga As Sb are selected as the source and drain materials of the P-type TFET.3)Finally,this article will use the new TFET device(TS-IG-TFET)proposed above to design high and low threshold devices.Because TS-IG-TFET is also an independent gate device with strong coupling between its back gate and front gate,it is possible to generate different logic by using different device threshold voltages,namely the proposed low threshold TS-The IG-TFET has an OR logic function,and the high-threshold TS-IG-TFET has an AND logic function,which can reduce the number of transistors in the circuit.This part will use Silvaco TCAD Atlas simulation software to analyze the performance of the proposed independent gate high and low threshold devices and verify their switching logic.In addition,simulation results also show that compared to silicon-based TFET devices,independent gate high-low threshold TFET devices have larger on-state currents and steeper sub-threshold slopes.This thesis uses Silvaco TCAD Atlas to verify and analyze performance of the proposed device.The results show that the proposed high-low threshold TS-IG-TFET has a larger on-state current and a steeper sub-threshold slope compared to traditional silicon-based TFET devices.In summary,this paper proposes a new type of TFET device(TS-IG-TFET).By increasing the tunneling area and tunneling probability,the on-state current of the TFET device is improved,and the device is used to design high and low threshold devices.The results show that TS-IGTFET has great potential and application prospects in low-power circuit design.