【摘要】 利用同步辐射光电子能谱(Synchrotronradiationphotoelectronspectroscopy,SRPES)和X射线光电子能谱(X-rayphotoelectronspectroscopy,XPS)技术,研究了金属Zn在6H-SiC表面的吸附和热氧化以及ZnO/SiC的界面形成过程。研究结果表明,在SiC表面沉积金属Zn的初始阶段,Zn可以夺取SiC衬底表面残留的氧并与之成键。随着Zn覆盖度的增加,表面具有金属特性。在2.0×10-4Pa的氧气氛中180℃温度退火下,覆盖的Zn会被部分氧化形成ZnO,还有部分Zn因其在真空中的低蒸发温度而逸出表面。在同样的氧气氛中600℃温度退火后,覆盖的金属Zn全部被氧化而生成ZnO。在氧气氛中退火时,衬底也会轻度氧化,从而导致在ZnO/SiC界面处存在一层很薄的Si的氧化层。根据得到的光电子能谱的实验结果,计算出ZnO/SiC异质结的价带偏移为1.1eV。更多还原

【Abstract】 The adsorption and the thermal oxidation of Zn on 6H-SiC surface and the interface formation of ZnO/SiC have been investigated by using synchrotron radiation photoelectron spectroscopy (SRPES) and X-ray photoemission (XPS). The results show that at the initial stage of Zn adsorption, Zn can capture and bond with O remaining on the SiC surface. With increasing of Zn coverage, the surface exhibits metallic characterization. When the deposited Zn film is annealed at 180℃ in oxygen flux with the pressure of 2.0×10-4 Pa, it could be partly oxidized to form ZnO. Part of Zn atoms could escape from the surface due to its low evaporation temperature in UHV condition. While annealed at 600℃ in same oxygen flux, the total deposited Zn atoms could be oxidized to form ZnO. During annealing process, the substrate is also oxidized, which induces a thin layer of silicon oxide existing at the interface of ZnO/SiC. By using the results of SRPES and XPS, the valence band offset of ZnO/SiC is calculated to be 1.1 eV.更多还原