Development of New Methods for Structural Analysis of Silicon/Oxide Interface and Silicon Surface

1.实验条件的建立：当Si/SiO_2样品浸泡在HF水溶液中时，当Si表面暴露在该溶液中时，阳极电流流动。我们发现，在一定的条件下，电化学测量给出了非常重复性的结果。不同条件下制备的Si/SiO_2界面的电化学分析不同条件下制备的Si/SiO_2样品具有不同的电化学性能。这一发现表明，电化学方法对界面结构非常敏感。对不同晶向的Si/SiO_2样品的分析结果表明，Si/SiO_2样品的电化学结果与硅片的晶向有一定的关系。基于Si/SiO_2界面的结构模型，成功地解释了晶向的依赖关系。此外，我们还成功地将电流与样品的退火态关联起来。这些观察结果验证了新发展的分析Si/SiO_2界面结构的方法的有效性。发展了一种新的硅表面结构分析方法。我们发现，当氢终止的硅表面被电化学氧化时，以氢终止的硅表面以逐层的方式被氧化。我们还发现，电流-电压曲线对硅样品的条件非常敏感。在此基础上，我们提出了一种新的硅样品结构分析方法。空气中有机污染物对硅表面的污染以及由此引发的硅表面的氧化。我们发现，硅表面的污染是从形成空气中的有机物质岛开始的。污染物引发了硅的氧化。

1. Establishment of the experimental conditions.When Si/Si0_2 samples are immersed in an aqueous HF solution, anodic current flows at the time Si surface is exposed to the solution. We found that under certain conditions, the electrochemical measurement gives very reproducible results.2. Electrochemical analysis of the Si/SiO_2 interface prepared under different conditions.The Si/SiO_2 samples prepared under different conditions show different electrochemical properties. This finding indicated that' the electrochemical method is very sensitive to the interfacial structure.3. Analytical results for the Si/SiO_2 samples with different crystalline orientations.The electrochemical results for the Si/SiO_2 samples showed certain relationship with the crystalline orientation of the Si wafer Based on the structural model for Si/Si0_2 interface, we succeeded in the explanation of the dependence on the crystalline orientation. In addition, we succeeded to correlate the current to the annealing of the samples. These observations verify the usefulness of the newly developed method for the analysis of the Si/Si0_2 interfacial structure.4. Development of a new method for the structural analysis of the Si surface.We found that Si surface terminated with hydrogen is oxidized in a layer-by-layer manner, when Si surface terminated with hydrogen is electrochemically oxidized. We also found that the current -voltage curve is very sensitive to the conditions of the Si sample. On the basis of the finding, we proposed a new method for the structural analysis of Si samples.5. Contamination of Si surface by organic contaminants included in air and oxidation of Si surface triggered by the contaminants.We found that the contamination of Si surface starts by forming islands of organic materials included in air. The contaminants triggered the oxidation of Si.