AlGaN/GaN横向肖特基势垒二极管的仿真与制作

基于GaN横向肖特基势垒二极管(SBD)的频率特性和应用的需要,设计了一种基于AlGaN/GaN异质结的横向SBD.利用Silvaco Atlas软件研究了 AlGaN势垒层的厚度和Al摩尔组分对异质结AlχGaN1-χ/GaN SBD电学性能的影响.仿真结果表明,SBD器件截止频率随Al摩尔组分的增加先增大再减小,当AlχGaN,1-χ层中Al摩尔组分为0.2～0.25,其厚度为20～30nm时,AlGaN/GaN SBD器件的频率特性最好.在仿真的基础上,设计制作出了肖特基接触直径为2 μm的非凹槽和凹槽型AlGaN/GaN横向空气桥SBD.通过直流I-V测试和射频S参数测试,提取了两种SBD器件的理想因子、串联电阻、结电容、截止频率和品质因子等关键参数,该平面 SBD可应用于片上集成和混合集成的太赫兹电路的设计与制造.

Simulation and Fabrication of Lateral AlGaN/GaN Schottky Barrier Diodes

Based on the frequency characteristics and application requirements of GaN lateral Schottky barrier diodes (SBDs), a lateral SBD based on AlGaN/GaN heterojunction was designed. The influences of AlGaN layer thickness and Al mole fraction on the electrical characteristics of the AlχGaN1-χ/GaN SBDs were studied based on Silvaco Atlas software. The simulation results show that the cutoff frequency of the SBDs devices increases firstly and then decreases with the increase of the Al mole fraction. When the Al mole fraction is 0.2-0.25 and the AlGaN layer thickness is 20 - 30 nm, the AlGaN/GaN SBD devices exhibit optimal frequency characteristics. Based on the simulation results, nonrecessed and recessed AlGaN / GaN lateral SBDs with air-bridge were designed and fabricated,in which the Schottky contact diameter was 2 μm. With the DC I-V and RF S-parameter measurements, the key parameters of the two types of SBDs were extracted, such as ideal factor, series resistance, junction capacitance, cutoff frequency and quality factor. The planar SBDs can be used in the design and manufacture of on-chip or hybrid integrated terahertz circuits.