Ni插入层对Ag/p-GaN界面接触性能的影响机理

Influence Mechanism of Ni Interlayer on Ag/p-GaN Interfacial Contact Performance

采用“牺牲Ni处理”的方法研究了Ni对Ag/p-GaN界面接触性能的影响机理。利用传输线法(TLM)、紫外分光光度计、X射线光电子能谱(XPS)以及二次离子质谱仪(SIMS)等表征方式对Ag/p-GaN界面层光电性能进行了研究。结果表明,牺牲Ni处理后p-GaN表面仍会残留少量的Ni并以Ni2O3的形式存在;p-GaN表面Ga2p3结合能峰位朝低能方向移动了0.3eV,提高了Ag/p-GaN间的欧姆接触性能。我们认为,界面处的Ni会优先和p-GaN表面Ga2O3氧化物中的O结合形成Ni2O3,进而降低了p-GaN表面费米能级,提高了Ag/p-GaN之间的欧姆接触性能。

The effect of Ni on the contact performance of Ag/p-GaN interface is studied by the method of ‘Ni-assisted treatment’. The photoelectric properties of Ag/p-GaN interfacial are investigated by means of transmission line method(TLM),UV spectrophotometer(UV),X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometer(SIMS). The results show that a small amount of Ni remains on the surface of p-GaN after Ni-assisted treatment and exists in the form of Ni2O3. The binding energy peak of Ga 2p3 on the p-GaN surface shifts 0.3 eV in the direction of low energy,which improves the Ohmic contact performance between Ag/p-GaN after Ni-assisted treatment. In our opinion,the Ni at the interface will preferentially combine with the O of Ga2O3 on the surface of p-GaN to form Ni2O3,thus reducing the Fermi level on the surface of p-GaN and improving the Ohmic contact performance between Ag/p-GaN.