Research On Optimization Design And Application Of The Vertical Field-Effect Transistor

Metal-oxide-semiconductor field-effect transistor(MOSFET)has become one of the important roles of modern information technology and industrial production as Moore’s law continues to evolve.However,as Moore’s law approaches the physical limits of the material,conventional planar MOSFET have suffered from a series of undesirable problems such as short-channel effect.Therefore,exploring novel MOSFET structures to satisfy the demand for high performance and high integration integrated circuits(ICs)is necessary.On this context,a novel vertical MOSFET based on silicon on insulator(SOI)and through-oxide vias(TOV)technology has been proposed,and the performance optimization is accomplished by adjusting the physical parameters as well as the current conduction mechanism.In the first part,the electro-thermal coupling simulation of the novel vertical MOSFET and its performance optimization are operated.Firstly,the electrical performance simulation of vertical MOSFET in the ideal condition is completed through drift-diffusion model,and then the electrical performance parameters are extracted.In addition,temperature is an important factor in the degradation of semiconductor device performance,the self-heating effect(SHE)on the electrical characteristics of the vertical MOSFET is estimated through electrothermal coupling simulation.The maximum temperature in the vertical MOSFET channel region can reach 410 K under on state.The performance of the vertical MOSFET is degraded by the temperature rise in the channel region,but the degradation is within an acceptable range.Finally,adjusting the device parameters to further analyze the balance between vertical MOSFET electrical performance and SHE in the future designs.Finally,through adjusting the device parameters,the further analyze about balancing the electrical performance of vertical MOSFET with SHE in future designs is operated.In the second part,a novel vertical tunneling transistor(TFET)based on the original vertical MOSFET structure by introducing band to band tunneling conduction mechanism is proposed to break through the subthreshold swing limit.Considering the drawback about low on-state current of TFET,referring to the energy band theory,the energy band bending between the source region and the channel region is aggravated by adjusting the gate work function,which increases the band-tunneling generation rate and thus the TFET on-state current.Further,through introducing a gate-source overlap structure to the original structure,additional vertical tunneling is introduced on the surface of the source and gate overlap regions.And the vertical TFET on-state current can be further increased by increasing the difference in the work function between the gate and source regions.The optimized vertical TEFT on-state current can reach 26.2μA with an average subthreshold swing as low as 36.2m V/dec,which has promising applications in low-power fast logic switching circuits.In the third part,an application scenario of the vertical MOSFET,namely one transistor one memristor(1T1R)cell is shown.The COMSOL multi-physics field coupling modeling approach is used to complete the physical simulation of resistive random access memory(RRAM)and parameters extraction.Combining the Verilog-A language with the extracted physical parameters,the compact model modeling and electrical performance simulation of 1T1 R cell are completed in SPICE software.And by modulating the gate voltage of the vertical MOSFET,the multilevel storge operation can be achieved in the 1T1 R cell.The simulation results show that the 1T1 R cell exhibits good low-power characteristics,providing a new direction for low-power memory chip circuit design.