Department of Micro and Nanosciences, Aalto University, PO Box 13500, FI-00076 Aalto, Finland.
Nanotechnology. 2017 Feb 24;28(8):085303. doi: 10.1088/1361-6528/aa5650. Epub 2017 Jan 3.
In this work, focused ion beam (FIB) lithography was developed for plasma enhanced atomic layer deposited (PEALD) silicon dioxide SiO hard mask. The PEALD process greatly decreases the deposition temperature of the SiO hard mask. FIB Ga ion implantation on the deposited SiO layer increases the wet etch resistivity of the irradiated region. A programmed exposure in FIB followed by development in a wet etchant enables the precisely defined nanoscale patterning. The combination of FIB exposure parameters and the development time provides greater freedom for optimization. The developed process provides high pattern dimension accuracy over the tested range of 90-210 nm. Utilizing the SiO mask developed in this work, silicon nanopillars with 40 nm diameter were successfully fabricated with cryogenic deep reactive ion etching and the aspect ratio reached 16:1. The fabricated mask is suitable for sub-100 nm high aspect ratio silicon structure fabrication.
在这项工作中，我们开发了聚焦离子束（FIB）光刻技术，用于等离子体增强原子层沉积（PEALD）的二氧化硅（SiO）硬掩模。PEALD 工艺大大降低了 SiO 硬掩模的沉积温度。FIB Ga 离子注入到沉积的 SiO 层中，增加了辐照区域的湿法刻蚀电阻率。在 FIB 中进行编程曝光，然后在湿法蚀刻剂中显影，可实现精确定义的纳米级图案。FIB 曝光参数和显影时间的组合为优化提供了更大的自由度。在所测试的 90-210nm 范围内，开发的工艺提供了高的图案尺寸精度。利用本工作中开发的 SiO 掩模，成功地使用深反应离子刻蚀（DRIE）制备了直径为 40nm 的硅纳米柱，其纵横比达到 16:1。所制备的掩模适用于亚 100nm 高深宽比硅结构的制备。
