Mallavarapu Akhila, Ajay Paras, Barrera Crystal, Sreenivasan S V
NASCENT Engineering Research Center, University of Texas at Austin, Austin, Texas 78758, United States.
ACS Appl Mater Interfaces. 2021 Jan 13;13(1):1169-1177. doi: 10.1021/acsami.0c17011. Epub 2020 Dec 21.
The semiconductor industry's transition to three-dimensional (3D) logic and memory devices has revealed the limitations of plasma etching in reliable creation of vertical high aspect ratio (HAR) nanostructures. Metal-assisted chemical etch (MacEtch) can create ultra-HAR, taper-free nanostructures in silicon, but the catalyst used for reliable MacEtch-gold-is not CMOS (complementary metal-oxide-semiconductor)-compatible and therefore cannot be used in the semiconductor industry. Here, for the first time, we report a ruthenium MacEtch process that is comparable in quality to gold MacEtch. We introduce new process variables-catalyst plasma pretreatment and surface area-to achieve this result. Ruthenium is particularly desirable as it is not only CMOS-compatible but has also been introduced in semiconductor fabrication as an interconnect material. The results presented here remove a significant barrier to adoption of MacEtch for scalable fabrication of 3D semiconductor devices, sensors, and biodevices that can benefit from production in CMOS foundries.
半导体行业向三维（3D）逻辑和存储设备的转型揭示了等离子体蚀刻在可靠创建垂直高纵横比（HAR）纳米结构方面的局限性。金属辅助化学蚀刻（MacEtch）可以在硅中创建超HAR、无锥度的纳米结构，但用于可靠MacEtch的催化剂——金——与互补金属氧化物半导体（CMOS）不兼容，因此不能用于半导体行业。在此，我们首次报告了一种质量与金MacEtch相当的钌MacEtch工艺。我们引入了新的工艺变量——催化剂等离子体预处理和表面积——以实现这一结果。钌特别理想，因为它不仅与CMOS兼容，而且已作为互连材料引入半导体制造中。本文给出的结果消除了在可扩展制造3D半导体设备、传感器和生物设备时采用MacEtch的一个重大障碍，这些设备可以从CMOS代工厂的生产中受益。
