Development and Application of a Silicon Film Chamber for Enhanced Microscope‐Type <scp>X</scp> ‐Ray Fluorescence ( <scp>μXRF</scp> ) Analysis

ABSTRACT Micro‐scale X‐ray fluorescence (μXRF) is a versatile tool for non‐destructive elemental quantification across materials science, environmental monitoring, and industrial analysis. Nevertheless, quantitative robustness can deteriorate under short acquisition times due to limited photon statistics, geometric instability, and absorption effects. A physically grounded strategy that enhances quantitative robustness without prolonging acquisition time is therefore highly desirable. Here, we systematically investigate a film‐assisted sample configuration in a microscope‐type XRF (XGT) system, focusing on acquisition time (100 s vs. 400 s) and supporting film thickness (0.1–0.3 mm) as adjustable analytical parameters. Using NaCl and DOPC‐derived phosphorus as model systems, detection success rates and concentration distributions were statistically evaluated. Under photon‐limited conditions (100 s), the supporting film significantly improved Na detection success rate ( p &lt; 0.05) and reduced dispersion for low‐fluorescence‐yield phosphorus signals ( p &lt; 0.01). Thickness‐dependent effects were element‐specific and persisted for phosphorus even at extended acquisition time. The observed trends reflect the combined influence of Beer–Lambert attenuation and counting statistics, demonstrating that absorption alone cannot explain the experimental behavior; mechanical stabilization and signal detection success rate jointly determine quantitative stability. These findings demonstrate that supporting film thickness should be regarded as an active optimization parameter in μXRF rather than a passive structural component. The proposed approach enables acquisition time reduction while preserving quantitative precision and provides broadly applicable guidance for enhancing robustness in rapid micro‐scale XRF analysis.