Non-Invasive Mask Removal by Femtosecond Laser: Pure Mechanical Stripping Achieved Via Shockwave-Induced Stresses

To circumvent this limitation, a strategic modification was introduced: a water layer was covered on the Cr mask to enhance shockwave-induced stresses, enabled purely mechanical stripping of Cr masks without damaging the surface roughness, damage threshold, or structure of substrates. Finite-element simulations validated that water confinement exponentially amplified shockwave-induced stresses by nearly two orders of magnitude compared to air, surpassing the fracture strength of the Cr mask and initiating its fracture and subsequent stripping.

This novel methodology, characterized by its non-invasiveness to substrates, absence of contamination, and operational simplicity, paves the way for application to more intricate mask structures.