The Research On GaN-Based Multi-Harmonic RTD Of Double Barrier

With the development of ?-nitride materials and nano-quantum devices,GaN-based resonant tunneling diodes(RTDs)are gaining more and more attention because they have better performance than GaAs-based RTDs,such as wider direct band gaps,large band offset,higher peak electron velocity,and higher critical breakdown voltage and thermal stability.Based on the detailed study of the crystal structure,polarization effects of GaN and the characteristics of NDR,the GaN with the initial facet a-plane is selected as the substrate and the double barrier single well(DBS)material structure of AlGaN/GaN/AlGaN.This structure will achieve multiple resonant tunneling characteristics in the lower bias voltage range,in other words,it has multiple NDR characteristics and defines this RTD as a multi-harmonic RTD.At present,there are not many reports on multi-harmonic RTD at home and abroad.The multi-harmonic RTD studied in this paper can be applied to the application of pure quantum logic circuits.This article takes GaN-based double barrier multi-harmonic RTD as the research object,and the device structure of the designed multi-harmonic RTD is simulated by Slivaco TCAD software.This paper focuses on the effects of symmetric and asymmetric double barrier structures on multi-harmonic RTD characteristics.In the symmetrical structure,the simulation results shows that due to the quantum size effect,the change of the potential well mainly affects the change of the number of multi-harmonic RTD negative resistance regions,so the appropriate potential well width can be selected according to the requirement of the number of multi-harmonic RTD negative resistance regions.The simulation results also show that the change of barrier thickness and barrier height affects multi-harmonic RTD peak current,valley current,peak voltage,valley voltage and so on,so choosing the appropriate barrier thickness and barrier height allows the multi-harmonic RTD to meet the needs of low voltage and low power consumption.In the asymmetric structure,this paper mainly studies the effects of different barrier thickness and different barrier height on the multi-harmonic RTD in the emitter and collector regions.The simulation results show that the requirement of low voltage and low power consumption of multi-harmonic RTD devices can be satisfied by increasing the thickness or height of the barrier layer of the emitter region while reducing the thickness or height of the barrier layer of the collector region.