标题： SiO$_2$的原子层蚀刻 使用顺序的 SF$_6$气体和 Ar 等离子体 显示英文标题

标题： Atomic layer etching of SiO$_2$ using sequential SF$_6$ gas and Ar plasma

摘要： 在不断推进半导体技术的过程中，对原子层工艺的需求催生了创新工艺，这些工艺已经在持续缩小特征尺寸中发挥了重要作用。 其中，原子层刻蚀（ALE）正获得越来越多的关注，它能够在原子层面精确控制材料的去除。 尽管某些热 ALE 已经实现了亚纳米级的刻蚀控制，但目前涉及等离子体步骤的实用 ALE 工艺往往由于高度协同的 ALE 半反应稀缺而存在较高的刻蚀速率。 为了克服这一限制，我们开发了一种在硅片上使用顺序纯六氟化硫（SF6$_6$）气体暴露和氩气（Ar）等离子体刻蚀的二氧化硅（SiO$_2$）原子层刻蚀工艺，在接近室温条件下，实现了大约 1.4 {\AA }/循环的稳定且一致的刻蚀速率。 在这个过程中，两个半周期反应单独作用时都不会产生刻蚀效果，只有当两者按顺序重复时才会发生刻蚀，这意味着 100% 的协同效应。 温度和等离子体功率窗口的识别进一步证实了我们 ALE 工艺的高协同性。 此外，多周期的详细形貌表征揭示了方向性刻蚀效应。 本研究为 SiO$_2$刻蚀提供了一种可靠、可重复且高度可控的 ALE 工艺，这在纳米制造工艺中具有广阔的前景。 显示英文摘要

摘要： In the relentless pursuit of advancing semiconductor technologies, the demand for atomic layer processes has given rise to innovative processes, which have already played a significant role in the continued miniaturization features. Among these, atomic layer etching (ALE) is gaining increasing attention, offering precise control over material removal at the atomic level. Despite some thermal ALE achieved sub-nm etching controllability, the currently practical ALE processes that involve plasmas steps often suffer from high etch rates due to the scarcity of highly synergistic ALE half-reactions. To overcome this limitation, we developed an ALE process of silicon dioxide (SiO$_2$) on a silicon wafer using sequential pure sulfur hexafluoride (SF6$_6$ gas exposure and argon (Ar) plasma etching near room temperature, achieving a stable and consistent etching rate of approximately 1.4 {\AA}/cycle. In this process, neither of the two half-cycle reactions alone produces etching effects, and etching only occurs when the two are repeated in sequence, which means a 100% synergy. The identification of temperature and plasma power windows further substantiates the high synergy of our ALE process. Moreover, detailed morphology characterization over multiple cycles reveals a directional etching effect. This study provides a reliable, reproducible, and highly controllable ALE process for SiO$_2$ etching, which is promising for nanofabrication processes.