Theoretical Analysis of Current Crowding Effect in Metal/AlGaN/GaN Schottky Diodes and Its Reduction by Using Polysilicon in Anode

There exists a current crowding effect in the anode of AlGaN/GaN heterojunction Schottky diodes, causing local overheating when working at high power density, and undermining their performance. The seriousness of this effect is illustrated by theoretical analysis. A method of reducing this effect is proposed by depositing a polysilicon layer on the Schottky barrier metal. The effectiveness of this method is provided through computer simulation. Power consumption of the polysilicon layer is also calculated and compared to that of the Schottky junction to ensure the applicability of this method.