Kim Jiho, Lee Jin-Kyun, Chae Boknam, Ahn Jinho, Lee Sangsul
Pohang Accelerator Laboratory, POSTECH, Pohang, 37673, Republic of Korea.
Department of Polymer Science and Engineering, Inha University, Incheon, 22212, Republic of Korea.
Nano Converg. 2022 Dec 2;9(1):53. doi: 10.1186/s40580-022-00345-3.
This article presents a technique of scattering-type scanning near-field optical microscopy (s-SNOM) based on scanning probe microscopy as a nanoscale-resolution chemical visualization technique of the structural changes in photoresist thin films. Chemical investigations were conducted in the nanometer regime by highly concentrated near-field infrared on the sharp apex of the metal-coated atomic force microscopy (AFM) tip. When s-SNOM was applied along with Fourier transform infrared spectroscopy to characterize the extreme UV- and electron-beam (e-beam)-exposed hydrogen silsesquioxane films, line and space patterns of half-pitch 100, 200, 300, and 500 nm could be successfully visualized prior to pattern development in the chemical solutions. The linewidth and line edge roughness values of the exposed domains obtained by s-SNOM were comparable to those extracted from the AFM and scanning electron microscopy images after development. The chemical analysis capabilities provided by s-SNOM provide new analytical opportunities that are not possible with traditional e-beam-based photoresist measurement, thus allowing information to be obtained without interference from non-photoreaction processes such as wet development.
本文介绍了一种基于扫描探针显微镜的散射型扫描近场光学显微镜（s-SNOM）技术，作为一种对光刻胶薄膜结构变化进行纳米级分辨率化学可视化的技术。通过高浓度近场红外光在涂覆金属的原子力显微镜（AFM）尖端的尖锐顶点上进行纳米尺度的化学研究。当将s-SNOM与傅里叶变换红外光谱一起应用于表征极紫外和电子束（e束）曝光的氢倍半硅氧烷薄膜时，在化学溶液中进行图案显影之前，可以成功地可视化半间距为100、200、300和500 nm的线和间距图案。通过s-SNOM获得的曝光区域的线宽和线边缘粗糙度值与显影后从AFM和扫描电子显微镜图像中提取的值相当。s-SNOM提供的化学分析能力提供了传统基于电子束的光刻胶测量无法实现的新分析机会，从而可以在不受诸如湿法显影等非光反应过程干扰的情况下获得信息。
