Terahertz Schottky barrier diodes based on homoepitaxial GaN materials

The Schottky barrier diodes based on homoepitaxial n-type GaN materials are fabricated for high-power terahertz multiplier applications. The dislocation density of the GaN homoepilayer is estimated to be about 2-3 orders lower than the typical dislocation density of hetero-epitaxial GaN, the defect density and square resistance are also reduced. So, the series resistance of the diodes is decreased. The air-bridge structure and the substrate thinning-down technique were adopted to reduce the parasitic parameters. The cut-off frequency (f_c) is improved to be above 1.2THz at zero bias by this method.