最後，我們提出一套適用於先穎透鏡量測的多點、多角度量測策略：選擇 AOI = 60° 作為穩定的基線，以及 AOI = 70° 作為敏感檢測奈米級非均勻性的量測條件。此方法能為薄膜與奈米結構元件提供穩健的線上製程監控，並加速光柵與先穎透鏡的設計優化。;This work develops an integrated workflow combining spectroscopic ellipsometry, the Tauc–Lorentz dispersion model, and rigorous coupled-wave analysis (RCWA) to comprehensively characterize amorphous silicon thin films and nanoscale periodic grating structures.
We first employ the Tauc–Lorentz formalism to fit ellipsometric Ψ and Δ spectra of amorphous silicon, achieving optimized film thickness (62.64 nm) and incidence angle (60.52 ° ). Physical self ‐ consistency of the extracted refractive index and extinction coefficient is confirmed via Kramers–Kronig relations. Next, using the RETICOLO RCWA solver, we systematically investigate the influence of 60°–70° AOI, duty cycle (0.3– 0.7), etch depth (91–111 nm), and grating period (726 nm vs. 1033 nm) on TE/TM reflectance and ellipsometric parameters across 250–1200 nm. Simulation and experimental data exhibit excellent agreement, revealing pronounced TM suppression at Brewster’s angle. Finally, we propose a multi‐point, multi‐angle measurement strategy for metalens metrology: AOI = 60° for a stable baseline and AOI = 70° for sensitive detection of nanoscale nonuniformities. This methodology offers robust in‐line process monitoring for thin ‐ film and nanostructured photonic devices and accelerates design optimization of gratings and metalenses.
