Molecular dynamics study of SiO2 nanohole etching by fluorocarbon ions
Molecular dynamics study of SiO2 nanohole etching by fluorocarbon ions
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DOI：
10.1116/6.0002380
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
C. Cagomoc;M. Isobe;S. Hamaguchi
中科院分区：
文献类型：
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作者：
C. Cagomoc;M. Isobe;S. Hamaguchi
随着半导体器件尺寸的不断缩小，在材料表面上制造纳米级器件结构提出了前所未有的挑战。在这项研究中，分子动力学模拟CF[公式：见正文]离子束蚀刻的SiO[公式：见正文]进行了碳掩模，以形成直径为4 nm的孔。据发现，当离子能量足够高并且蚀刻继续时，通过离子束蚀刻形成锥形孔。这是因为在这些条件下的蚀刻基本上是由于物理溅射，使得具有高蚀刻产率的锥形表面随着侧壁和溅射的含Si物质的再沉积而出现。此外，发生从SiO[式：见正文]表面优先除去氧，这导致形成富Si侧壁表面。还发现，在同时照射CF[分子式：见正文]自由基的情况下，通过高能CF[分子式：见正文]离子束对平坦SiO[分子式：见正文]表面的蚀刻产率可以加倍，但是CF[分子式：见正文]自由基的通量过大会导致蚀刻停止。
As the sizes of semiconductor devices continue to shrink, the fabrication of nanometer-scale device structures on material surfaces poses unprecedented challenges. In this study, molecular dynamics simulations of CF[Formula: see text] ion beam etching of SiO[Formula: see text] were performed with carbon masks to form holes with a diameter of 4 nm. It is found that, when the ion energy is sufficiently high and the etching continues, tapered holes are formed by the ion beam etching. This is because the etching under these conditions is essentially due to physical sputtering, so that tapered surfaces having high etching yields appear as the sidewalls and sputtered Si-containing species are redeposited. Furthermore, preferential removal of oxygen from SiO[Formula: see text] surfaces occurs, which leads to the formation of Si-rich sidewall surfaces. It is also found that, with simultaneous irradiation of CF[Formula: see text] radicals, the etching yield of a flat SiO[Formula: see text] surface by energetic CF[Formula: see text] ion beams can double, but too large a flux of CF[Formula: see text] radicals causes etch stop.