KOH溶液处理对AlGaN紫外探测器暗电流的影响

The effect of KOH solution process on dark current of AlGaN ultraviolet photodetectors

采用KOH溶液表面处理工艺制备得到了128×1线列日盲AlGaN紫外探测器,器件的反偏暗电流为6.88×10-9A(-8 V时),比未采用此项工艺制备得到的器件的暗电流减小近103倍。元素深度分布俄歇电子谱(AES)等测试结果分析表明,采用这种表面处理工艺可以有效地去除干法刻蚀后材料表面的N空位、刻蚀生成物及自然氧化物,减小了界面态密度,改善了电流-电压特性,减小了反偏暗电流。利用传输线模型TLM计算得到了Ti/Al/Ti/Au金属电极与高Al组分n-Al0.65Ga0.35N材料间的接触电阻率为8.35×10-3Ωcm2。

A high electrical performance 128×1 solar-blind ultraviolet photodiode was fabricated by the KOH solution surface process.The dark current with the dropping about 3 orders is 6.88×10-9A at reverse bias 8 V by using the surface process technology.The results of SEM and AES measurements have shown that the KOH solution surface process can efficiently remove the N vacancies,dry-etched products and native oxides,which reduces the density of interface states,improves the current-voltage characteristics and reduc...