研究了多层Ti/Al结构电极对GaN/AlGaN HEMT欧姆接触特性及表面形态的影响。采用传输线模型对各结构电极的比接触电阻率进行了测量，采用扫描电子显微镜对电极表面形态进行扫描。实验结果显示，在同样的退火条件下，随着Ti/Al层数的增加，比接触电阻率逐渐减小，表面形态趋于光滑；降低Ti/Al层的厚度会加剧Au向内扩散而增加比接触电阻率，但能稍微改善表面形态；Ti比例过高会影响TiN的形成导致比接触电阻率增加，但能明显改善表面形态。

The effect of multilayer Ti/Al structure electrode on AlGaN/GaN HEMT Ohmic contact characteristics and the surface morphology were investigated. The specific contact resistance of all kinds of electrode structure was measured by transmission line model (TLM). The scanning electron microscope (SEM) was used to measure the electrode surface morphology. The experiment results show that the special contact resistance tend to decrease and the surface morphology tend to be smooth with the increasing of the number of Ti/Al layers in the same annealing conditions. The reducing of the thickness of Ti/Al layer can increase the specific contact resistance because of Au in-diffusion, but can slightly improve the surface morphology. High Ti ratio can reduce the formation of TiN, and lead to the increasing of specific contact resistance, but can greatly improve the surface morphology.