AlGaN肖特基势垒二极管的研制

Fabrication and investigation of AlGaN-based Schottky barrier diode

为研制适合高温高压下工作的整流器件,利用金属有机化学气相淀积(MOCVD)技术生长的AlGaN/GaN/蓝宝石材料,采用电子束蒸发的方法,用Au和Ti/Al分别作为肖特基接触和欧姆接触的电极,制备了AlGaN肖特基二极管,并对其工艺过程和器件特性进行了研究.IV测试表明该AlGaN肖特基二极管具有明显的整流特性和较高的反向击穿电压(95V),理想因子为1.93.经300℃1min退火,该器件正、反向IV特性都得到明显改善.采用变温IV法对Au/AlGaN接触的肖特基势垒高度进行了标定,其势垒高度高达1.08eV,更适合在高压、大电流条件下工作.

The AlGaN-based Schottky barrier diode was fabricated using electron beam deposited Au and Ti/Al as the Schottky contact and ohmic contact respectively for high power and high temperature applications such as microwave mixers and rectifiers. And the AlGaN/GaN/sapphire was grown by metal organic chemical vapor deposition (MOCVD). Measurements of the I-V characteristics of the diode show that the device has good rectifying property, high breakdown voltage of 95 V and ideal factor with value of 1.93. The forward and reverse current characteristics were improved greatly after annealing at 300°C for 1 min. The barrier height of the Au/AlGaN Schottky contact was as high as 1.08 eV by analysis of various I-V curves under corresponding temperatures. The results show that the device can be used in high power and large current rectification.