金属Sn氧化薄膜的真空退火与原位XPS测量

Vacuum Annealing and in-Situ XPS Measurement of Oxidized Sn Films

本文研究了在真空退火过程中金属Sn氧化薄膜表面L元素Sn和O的化学性质．利用X射线光电子能谱（XPS）的表面分析方法，发现在金属Sn氧化薄膜的表面上存在大量的吸附氧粒子（O-和）提高真空退火温度，吸附氧粒子的数量增加；同时吸附氧粒子的负电性变弱．当退火温度低于350℃时，吸附氧粒子数量的增加是起因于SnO2→Sn2O3的转变；在这种情况下，可以观察到Sn2O3是相对稳定的金属Sn氧化物，继续提高退火温度，达到400℃时，Sn在金属Sn中的相对含量急剧增大，Sn在金属Sn中相对含量增加的原因与金属Sn的价态Sn3+→Sn0的转变相关在这个转变过程中伴随着O的释放和薄膜表面氧粒子的进一步堆积．与温度低于350℃时的退火条件相比，XPS的测量也发现，在400℃的退火温度下；SnO2相对于Sn2O3反而成为比较稳定的金属Sn氧化物．还讨论了金属Sn氧化薄膜表面上吸附氧粒子的吸附状态以及吸附状态与退火温度的关系．

The dependence of chemisitry properties of elements Sn and O on the surface of oxidized Sn films on vacuum annealing was studied. By usillg in-situ measurements of X-ray photoelectron spectroscopy (XPS), it was found that great number of negatively charged particles (such as O- and O2) were adsorbed on the surface. The amount of the adsorbed oxygen particles increased with the annealing temperature (Tann), and then the adsorbed oxygen particles became less charged.The increase in the number of the adsorbed oxygen particles is attributed to the transition from SnO2 to Sn2O3 as Tann 5350℃. At 350 Tann 400℃, the relative content of Sn in metallic Sn phase increased suddenly with Tann due to the transition from Sn3+ to Sno, which resulted in releasing and successively piling up of O particles adsorbed on the surface. Aloreover, SnO2 became more stable than Sn2O3 in the case of higher annealing temperauters, as say Tann 250℃. The adsorbed states of the oxygen Particles on the surface and the correlation between the adsorbed states and annealing temperature were also discussed.