Research On A Novel GaN-Based Diode

RTD has the advantages of high-frequency,high-speed,differential negative resistance,bistable self-locking,and can be designed and manufactured by conventional IC technology,and has attracted the attention and research of scholars in recent years.In the process of improving the performance of GaN-based RTD,we have discovered a GaN-based RTD that exhibits dense continuous current oscillation characteristics in the high voltage region.The electrical oscillation characteristics of the new RTD are very similar to the optical Franz-Keldysh oscillation.Therefore,the RTD having such current oscillation characteristics is called Franz-Keldysh oscillating diode,abbreviated as FKOD.The study of the dense current oscillation characteristics of FKOD in the high bias region may have important theoretical and practical significance for the development of quantum logic applications oriented to human brain thinking and the research direction of quantum logic circuits based on FKOD.This paper focuses on the microscopic mechanism of current oscillation characteristics of FKOD devices.We designed the basic structure of a GaN-based FKOD device with a double-barrier single well structure,and firstly established a physical model of FKOD devices for 1D Schrodinger-Poisson equation with polarization effect.Then we numerically solved and verified the model through Silvaco TCAD.By analyzing and summarizing the simulation results of the bound state energy distribution of FKOD devices under different bias voltages,we find an unconventional quantum size effect that is not the same as the quantum size effect in RTD devices.The unconventional quantum size effect shows the variation of the transition state energy level in the potential well with the change of the applied bias voltage,such as hopping,degeneracy and splitting.lt is one of the important theories to reveal the microscopic mechanism of FKOD devices.Then,comprehensively analyze the simulation results of the energy band distribution of the devices,the distribution of the electron wave function in the well,the change of the energy level of the bound state,and the change of the transmission coefficient under different peak and valley biases,we finally conclude that the bound state energy level of the main resonant tunneling in the well decreases and the transmission coefficient periodically oscillates with the increase of the bias voltage,both causing the continuous oscillation of current in the high voltage region in the FKOD devices.By comparing and analyzing a large number of simulation test results,We have obtained the law that the variation of structural parameters such as the width of the functional layer,the depth of potential well and the height of potential barrier,the heavily doped concentration in the emitter region,and the built-in polarization electric field generated by the polarization effect on the volt-ampere characteristics of FKOD devices,which will provide a reference for optimizing the performance of FKOD devices in the future.