低覆盖度的Au/GaN(0001)界面的同步辐射研究

利用同步辐射光电子能谱研究了低覆盖度Au在GaN(0001)表面的初始生长模式,肖特基势垒高 度以及界面的电子结构.结果表明，Au沉积初始阶段有界面的化学反应,随后呈三维岛状生长 .由光电子能谱实验确定的肖特基势垒高度为14 eV. 通过对界面价带谱和Au 4f芯能级谱 的分析,确定了界面化学反应的存在.利用线性缀加平面波方法计算了GaN(0001)和Au的价带 态密度并分析了化学反应产生的机理,认为在初始阶段界面形成了Au_Ga合金. 关键词： 同步辐射 光电子能谱 Au/GaN欧姆接触 态密度

Synchrotron radiation study on Au/GaN(0001) interface with low coverage

Synchrotron radiation photoemission spectroscopy (SRPES) is used to study the in itial growth mode of the gold deposition on the surface of GaN, the Schottky bar rier height (SBH) and the electronic structure at the interface of the Au/GaN(00 01) system. The results show that at the initial stage chemical reaction exists between the Au and GaN substrate. Over the reaction layer, the growth mode of Au deposition is 3D island mode. The SBH is examined by the SRPES and the result i s 14eV, which is consistent with other experiment reports. Analyzing the ene rgy shift of valence band and the Au core level, the interface chemical reaction is confirmed. The theoretical calculation by linear augmented plane wave method gives the density of states. According to the calculation results, the principl e of the interface reaction is discussed.