Hydrogen plasma-induced blistering on aluminum: morphology, growth, and interfacial energetics

Hydrogen blistering presents critical reliability concerns in space, nuclear, and semiconductor applications. While prior studies focused on the blister initiation mechanism of nanoscale samples under electron-induced plasma, yet whether similar blistering behavior and mechanism also occur under conventional plasma conditions on bulk materials remain elusive. Here, we show that hydrogen plasma induces extensive blistering on bulk aluminum surface. Atomic force microscopy reveals self-similar blister growth with a nearly constant aspect ratio, consistent with Föppl–von Kármán theory, enabling quantitative extraction of the adhesion energy (Γ ≈ 4.83 J/m²). We identify two coalescence-driven growth modes—lateral contact- and vertical pile-up-coalescences, and observe blister boundaries with straight segments aligned with crystallographic directions. These features suggest that subsurface nanocavities bounded by low-index facets locally pin the oxide cap. Our findings provide new insights into hydrogen-induced blistering and film delamination and highlight the role of substrate crystallography in shaping interfacial failure.