Simulation study for anode engineering of AlGaN/GaN double-channel hybrid anode Schottky barrier diode

Abstract

In this work, a new structure of double-channel hybrid anode Schottky barrier diode with dual anode metal (DCH-DM-HAD) was proposed, and the preliminary investigation of the device's electrical characteristic was conducted by using Silvaco TCAD tools. The double-channel hybrid anode diode (DCH-HAD) and single channel hybrid anode diode (SCH-HAD) were compared and it was found that the Ron at lower forward bias is twice as large as the higher bias, which is attributed to different Von of upper channel and lower channel. It can be avoided by setting different metal structures at anode. Besides, the Von decreases with increasing thickness of the barrier layer, but the reverse leakage current increases fast. Finally, the breakdown voltage of three different structures of hybrid anode diodes were compared, and it is found that replacing nickel with tungsten is harder to form uniform electric field due to difference of workfunction of tungsten and nickel. Nonetheless, these kinds of diodes own excellent electrical characteristics.