低电阻GaN基太赫兹空气桥结构平面肖特基二极管

Low Resistance GaN-Based Terahertz Air-Bridge Structure Planar Schottky Diode

提出了通过增大欧姆接触电极包围角提高GaN基太赫兹肖特基二极管的截止频率的方法,该方法减小了空气桥结构平面肖特基二极管的串联电阻,进而提高了器件的截止频率。设计并制备了不同欧姆接触电极包围角的空气桥结构平面肖特基二极管,通过对器件I-V特性及C-V特性的测量,可知随着欧姆接触电极包围角的增大,肖特基二极管的串联电阻减小,而肖特基二极管的总电容并没有受影响。欧姆接触电极全包围结构的肖特基二极管截止频率为264 GHz,约为欧姆接触电极包围角为180°器件的1.6倍。

The method of increasing the ohmic contact electrode surrounding angle was proposed to improve the cut-off frequency of GaN-based terahertz Schottky diodes.It can reduce the series resistance of the air-bridge planar Schottky diodes, and thus increase the cut-off frequency of the devices.The air-bridge planar Schottky diodes with different ohmic contact electrode surrounding angles were designed and fabricated.The measurements of the I-V characteristic and C-V characteristic of the diodes show that the series resistance of Schottky diodes decreases with the increase of the ohmic contact electrode surrounding angle, while the total capacitance is not affected.The cut-off frequency of Schottky diode with ohmic contact electrode completely surrounding structure is 264 GHz, which is about 1.6 times higher than that of the one with 180° ohmic contact electrode surrounding angle.