Quantifying O₂/Ar plasma-modified surface energy of Si/SiO₂/Si₃N₄ via ZnS-nanobelt adhesion mechanics

Plasma treatment is a widely used strategy to tailor the surface energy of semiconducting and dielectric substrates, yet accurately quantifying these changes remains a challenge due to the complex surface chemistry and interface interactions involved. In this study, we employ ZnS nanobelts as sensitive probes in a nanobelt bridging method to quantitatively evaluate the surface energy of smooth Si, SiO2, and Si3N4 substrates before and after short-duration (30 s) oxygen and argon plasma treatments. While atomic force microscopy reveals negligible changes in surface roughness post-treatment, the bridging method uncovers significant increases in surface energy, far exceeding those measured by conventional water contact angle method. This discrepancy highlights the bridging method’s enhanced capability to assess nanoscale interfacial interactions, especially those mediated by surface charges or polarization effects introduced by plasma exposure. Theoretical analysis suggests that the nanobelt-substrate interface captures not only van der Waals forces but also electrostatic contributions often overlooked by macroscale liquid-solid contact measurements. Moreover, the nanobelt bridging approach offers a powerful alternative for probing plasma-induced surface energy modifications, particularly for materials or device platforms where electrostatics play a dominant role. These findings also provide important insights into the adhesion behavior of nanoscale building blocks in micro/nanoelectromechanical systems and related micro/nanodevices.