Ni层厚度对p-GaN/Ni/Au欧姆接触特性的影响

对p-GaN/Ni/Au欧姆接触特性与Ni金属层厚度之间的相关性进行了对比实验研究,利用XRD衍射结果与表面金相显微分析手段对Ni/Au双层金属电极在合金退火过程中的行为特性进行了细致探讨。分析结果表明:在Ni/Au电极结构中,由双层互扩散机制与NiO氧化反应机理决定,Ni层与Au层之间的厚度比率对p型GaN欧姆接触特性的优劣有重要影响,在Ni、Au层厚度相当时可获得最佳的p型欧姆接触。

Effects of Ni-layer Thickness on the Characteristic of p-GaN/Ni/Au Ohmic Contact

In this work, the interrelation between the thickness of Ni metal layer and the characteristics of p-GaN/Ni/Au ohmic contact was experimentally studied. The behaviors of Ni/Au double-layer metal electrode in alloyed annealing process were discussed by XRD and metallographic methods. It is revealed that, due to the mechanisms of metal inter-diffuse and Ni-O oxidation, the ratio of Ni/Au layer thickness plays an important role in determining the characteristic of p-GaN/Ni/Au ohmic contact. According to the results, the best p-GaN/Ni/Au ohmic contact can be attained when the thickness of the double metal layers is equal approximately.