電界効果トランジスタゲートスタック絶縁膜形成機構と絶縁破壊機構統合モデルの研究

利用同步辐射实时X射线光电子能谱（XPS）研究了Si（001）表面的快速高温氧化动力学，同时观察了氧化过程中SiO2的生长速率和界面应变。据观察，SiO2的生长速率提高了5.0倍的冷却温度。通过扩展统一的Si氧化反应模型，可以很好地解释SiO2氧化物生长动力学，其中氧化物生长速率dRSiO 2/dt与界面应变的增加成正比。这意味着在低温下氧化物新生长的地方周围容易发生进一步的氧化，导致SiO2/Si界面形貌的粗糙化。利用XPS、紫外光电子能谱和扫描隧道显微镜对生长在Si（001）和Si（111）表面上的氧化物薄膜的热分解动力学进行了实验研究，从分解诱导应变的角度阐明了空穴的成核和生长反应机制。据观察，应变Si原子的量增加成比例的氧化物分解期间的空隙成核的量。这是解释通过使用一个建议的分解模型，其中有一个下冲的轮廓的应变在周围的积累空洞面积和下冲应变的大小增加成比例的空位的量。在上述研究的基础上，统一的Si氧化反应模型包括氧化物生长和氧化物分解进行了验证和进一步扩展。

The rapid temperature oxidation kinetics on Si(001) surfaces was investigated by real-time X-ray photoelectron spectroscopy (XPS) using synchrotron radiation to observe the SiO2 growth rate and interfacial strain simultaneously during oxidation. It was observed that the SiO2 growth rate was enhanced 5.0 times by cooling temperature. The SiO2 oxide growth kinetics is interpreted well by extending the unified Si oxidation reaction model, where oxide growth rate dRSiO2/dt is in proportion to the increase of the interfacial strain. This implies that further oxidation is prone to occur around the place where oxides are newly grown at low temperature, leading to a roughening of the SiO2/Si interface morphology. The thermal decomposition kinetics of very thin oxide layers grown on Si(001) and Si(111) surfaces were investigated experimentally by XPS, ultraviolet photoelectron spectroscopy and scanning tunneling microscopy to clarify the void nucleation and growth reaction mechanisms from a viewpoint of the decomposition-induced strain. It was observed that the amount of strained Si atoms increased in proportion to the amount of oxide decomposed during the void nucleation. This was interpreted by using a proposed decomposition model, where there is an undershoot profile of the strain at the periphery of the accumulated void area and the magnitude of the undershoot strain increased in proportion to the amount of vacancies.Based on the above studies, the unified Si oxidation reaction model consist of both the oxide growth and oxide decomposition was verified and further extended.