砷化镓半导体表面自然氧化层的X射线光电子能谱分析

用X射线光电子能谱(XPS)，测量了Ga3d和As3d光电子峰的结合能值，指认了砷化镓(GaAs)晶片表面的氧化物组成，计算了表面氧化层的厚度，定量分析了表面的化学组成；比较了几种不同的砷化镓晶片表面的差异。结果表明：砷化镓表面的自然氧化层主要由Ga2O3、As2O5、As2O3和单质As组成，表面镓砷比明显偏离理想的化学计量比，而且，氧化层的厚度随镓砷比的增大而增加；溶液处理后，砷化镓表面得到了改善。讨论了可能的机理。

X-Ray Photoelectron Spectrocopic Analysis of Native Oxides Layer on Gallium Arsenide Semiconductor Surface

X-ray photoelectron spectroscopy (XPS) was used to analyte native oxides layer on gallium arsenide (GaAs) surface. The Ga3d and As3d binding energies associated with some compounds were measured. The oxides present on the GaAs surface were identified. A measurement method of Ga/As atomic ratio and oxide layer thickness was developed. A series of GaAs polished wafers and GaAs wafers treated with some chemical solutions were studied by XPS. The results show that the native oxide layer on GaAs surface is composed of Ga 2O 3As 2O 5As 2O 3 and elemental As; and the Ga/As atomic ratio is drifted off the stoichiometry far away. The thickness of oxide layer on GaAs surface increases with increasing the Ga/As atomic ratio. After treated with some chemical solutions, the GaAs surface is modified. The formation mechanism of surface oxide in the air was also discussed.