Design And Research Of Analog Circuits Based On Tunneling FET Devices

According to the guidance of Moore's Law,the feature size of devices in integrated circuits has continued to decrease.In recent years,the gate length of transistors has reached nanometers.At this level,small size effects have become more and more serious.Gate tunneling effects,polysilicon gate depletion effects,and drain induced barrier reduction effects have become the biggest obstacles to Moore's Law.To overcome the small size effect at the nanometer level,researchers have widely studied TFETs based on the principle of quantum tunneling.TFETs can theoretically break through the limit of thermoelectric potential and obtain sub-threshold swings below 60mV/dec at room temperature,leading to a very high current switching ratio.Above-mentioned advantages make TFETs the most promising for the next generation of most extensively used devices in integrated circuits.However,the research on TFET at home and abroad focus on device structure and material characteristics.Focus on the low subthreshold swing and high switching ratio characteristics of TFETs,and use them in the field of digital circuits,and the research on TFETs in the field of analog circuits has not been fully developed yet,this article aims at the current vacancy of TFET in the field of analog circuit research,and based on the device structure of previous stage research results,GFP-TFET and Lateral TFET have been modeled and compared with MOSFET,then TFET-based analog circuit units have been built,analyzed their advantages and disadvantages in analog applications.The main research contents of this article are as follows:The device characteristics of Lateral TFET and GFP-TFET are simulated,and the DC,AC,parasitic and intrinsic parameters of three different devices are simulated and analyzed based on the simulation data.The feasibility of the application of TFET device characteristics in circuits has been studied.Besides,the analysis focuses on the differences in threshold definition between TFET and MOSFET,analyzes the definition of gate threshold voltage and drain threshold voltage in TFET,and extracts the gate threshold voltage and drain threshold voltage for the two types of TFET.Secondly,the transconductance generation efficiency parameters of the three transistors are extracted,and the performance tradeoffs of the three devices in transconductance generation efficiency are studied.Finally,scaling down rules of TFET are illustrated and discussed,and characteristics of 5nm TFET are demonstrated as follows.To further analyze the application of TFETs in analog circuits,considering three analog units and their applications: a transmission gate,a current mirror,and an operational transconductance amplifier as examples,the corresponding circuit structure is built according to three different devices,and the gm/I design methodology is used in the circuit design.The results show that the asymmetric source-drain structure of the TFET makes the transmission gate need to be changed to a double N-type symmetric structure,and the ultra-low subthreshold swing,low leakage,large output resistance,and extremely high transconductance generation efficiency of the TFET make its current mirror and operational transconductance amplifier have higher output resistance and high gain.Under the same circuit performance circumstance,TFET can replace the complex circuit structure of MOSFET with a simple circuit structure,making circuit simple and small while reducing power consumption.Finally,based on the modules built by the TFET,a sample-and-hold amplifier circuit was built by three units above-mentioned,which SFDR are 58.04 dB.