Chein, Wei HsinWei HsinCheinYang, Fu ShengFu ShengYangThakur, KomalKomalThakurWu, Guo WeiGuo WeiWuLIANG-CHIA CHEN2023-06-072023-06-072022-01-0197815106515000277786Xhttps://scholars.lib.ntu.edu.tw/handle/123456789/631919The article presents a novel optical metrology method for accurate critical dimension (CD) measurement of sub-micrometer structures with high spatial resolution and light efficiency. The proposed method takes advantage of the spatially coherent nature of the supercontinuum laser to detect submicron-scale structures with high aspect ratios. By using the method, CD measurement of individual microstructures such as vias and redistribution layers (RDL) becomes achievable when a high magnification optical configuration is incorporated. Proved by a test run on measuring submicron structures with linewidths as small as 0.7 and an aspect ratio over 4, the measurement precision of the depth can be kept within a few nanometers.critical dimension metrology | high aspect ratio structures | Spectral reflectometry | supercontinuum laser[SDGs]SDG11conference paper10.1117/12.26218952-s2.0-85132969724https://api.elsevier.com/content/abstract/scopus_id/85132969724