Research And Structure Design Of Hybrid Crystal Orientation Channel Strained TFET

Following Moore's Law,the feature size of traditional metal-oxide-semiconductor field-effect transistor?MOSFET?integrated circuit chip continues to shrink,and device integration gradually increases.However,as the performance of the chip increases,the power consumption problem becomes more and more serious.Based on the principle of carrier drift diffusion,the subthreshold swing of a traditional MOSFET at room temperature cannot be lower than 60mV/dec.When the device is scaled down in proportion,the off-state leakage current of the device is significantly increased,which in turn increases the static power consumption of the device.It is not conducive to the further improvement of device integration.The tunneling field effect transistor?TFET?based on the carrier band-to-band tunneling effect is not limited by subthreshold swing of 60mV/dec,the switching speed is fast,the off-state leakage current is small,and the power consumption of the device is low.It is suitable for very large scale integrated circuits.However,compared with the traditional MOSFET,the on-state current of the TFET is usually about 2 to 3 orders of magnitude lower,which limits the practical application of the TFET.This article will study the effective measures to increase the on-state current of the TFET.The main work of this paper is as follows:Firstly,for the effect of the carrier effective mass on the band-to-band tunneling of the TFET,it is proposed that the carrier with the smaller effective mass crystal orientation is selected for tunneling,so that a greater carrier band-to-band tunneling probability is obtained.In view of the effect of material band gap width on TFET band tunneling,a uniaxial stress was introduced into the device through contact etch stop layer?CESL?strain technology to adjust the energy band structure to obtain a smaller band gap width and effective carrier mass,thereby increasing the carrier tunneling probability.Secondly,a simulation study of a typical lateral structure TFET device is performed.On the common?100?crystal surface,there exists both<100>and<110>crystal orientation.It is found that the on-state current of the device is greater when the channel crystal direction of the device follows the<110>orientation.Uniaxial stress is introduced into the device through CESL strain technology.Both uniaxial tensile stress and uniaxial compressive stress can increase the on-state current of the device.Finally,a trench gate TFET structure is proposed.The performance difference between hybrid crystal and nonhybrid crystal trench gate TFET,and the influence of the key structural parameters of hybrid crystal trench gate TFET on device performance are investigated.Enhance the performance of hybrid crystal trench gate TFET with CESL strain technology and electric field concentration effect.The on-state current of the device reached 5.25×10^-5A/?m,and the average subthreshold swing was 85.5mV/dec.