Density Functional Theory Study on Stability of Fe, Cu, and Ni Atoms Near (001) Surface of Si Wafer
Density Functional Theory Study on Stability of Fe, Cu, and Ni Atoms Near (001) Surface of Si Wafer
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硅片(001)面附近Fe、Cu、Ni原子稳定性的密度泛函理论研究
DOI：
10.1149/2.0111910jss
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发表时间：
2019
影响因子：
2.2
通讯作者：
Sueoka Koji
中科院分区：
文献类型：
--
作者：
Nonoda Noriyuki;Sueoka Koji
“金属吸杂”技术对于保持最先进的电子器件的有源区非常清洁变得越来越重要。如果内部吸杂（IG）不能很好地工作，则进入硅（Si）晶片的金属原子将在晶片表面向外扩散。因此，除了理解IG机制之外，理解Si（001）晶片表面附近的金属原子的稳定性也很重要。采用密度泛函理论计算了在有和没有超薄氧化膜的情况下，Fe、Cu和Ni原子在（001）面附近的稳定性.主要结果如下。(1)与Si块体相比，Fe、Cu和Ni原子从Si（001）表面直到第五原子层更稳定。(2)与被B原子内部吸杂的原子相比，晶片表面的Fe 0、Fe+、Ni 0和Cu 0原子在能量上非常稳定，其顺序为Fe 0> Fe+> Ni 0> Cu 0，而Cu+在晶片表面不那么稳定。(3)在超薄Si氧化物膜的正下方，Fe、Cu和Ni原子的形成能增加。此外，这些金属之间的表面区域和硅体的偏析系数进行了评估。
" Metal gettering" technology is becoming increasingly important to keep the active region of state-of-the-art electronic devices extremely clean. Metal atoms entering the silicon (Si) wafer will be out-diffused at the wafer surface if the internal gettering (IG) does not work well. Therefore, an understanding the stability of metal atoms near the Si (001) wafer surface is important in addition to understanding the IG mechanism. The calculations with density functional theory are preformed to investigate the stability of Fe, Cu, and Ni atoms near the (001) surface with and without ultra-thin oxide film. The following main results are as obtained.(1) Compared to the Si bulk, Fe, Cu, and Ni atoms are more stable up to the fifth atomic layer from the Si (001) surface.(2) Fe 0, Fe+, Ni 0, and Cu 0 atoms at the wafer surface are energetically very stable compared to those internally gettered by B atom, with the order of Fe 0> Fe+> Ni 0> Cu 0, while Cu+ is not so stable at the wafer surface.(3) Just below the ultra-thin Si oxide film, the formation energy of Fe, Cu, and Ni atoms is increased. Furthermore, the segregation coefficient of these metals between the surface region and Si bulk was evaluated.