摘要
用STM观测了Si（100）表面被氧气流携带的HF和H2O处理后的表面原子结构．实验在大气环境和室温条件下进行，所得STM拓扑图具有清晰的原子级的分辨率．结果表明处理后的表面结构随时间发生变化．刚处理后的表面不显示有序的结构特征，但在大气中存放15分钟后，硅片表面开始逐渐呈现出清晰的Si（100）2×1结构，随后再逐渐转变为1×1结构．这可能是混合气体与Si表面作用，能更有效地清除表面残余的沾污物和氧化层，暴露清洁的硅2×1再构表面，进一步由于吸附H，使表面悬挂键被氢原子占据，转变为1×1结构．有序结构可维持3小时，因此用所述混合气体处理硅片是更有效清洁和钝化硅表面的一种方法．
The atomic structures of Si(100) surface treated by the gas mixture of HF, O2 and H2O are studied by STM. The experiments are carried out in air at room temperature. The STM images are obtained with atomic resolution. The results show that the surface structure changed with time. The surface structure is disorder at the outset, but it is transformed into Si (100) 2 × 1 structure gradually after 15min, and then, Si (100) 2 × 1 structure would be transformed into 1× 1 structure further. The ordered surface structure would be stable about 3h until it become disorder again due to oxidation. The results indicate that the treatment of Si surface with gas mixture of HF, O2 and H2O is a more effective method for cleaning the Si surface.
基金
国家自然科学基金
