EUV Mask Critical Dimension Adjustment via Laser-Induced Chemical Etching

The patent introduces a liquid film as an intermediary medium between the laser beam and the EUV mask. The liquid film absorbs the laser beam energy and converts it to thermal energy, which then facilitates chemical etching of the mask pattern. This intermediary approach allows indirect laser interaction with the mask, overcoming the fundamental limitation of EUV light absorption while enabling effective pattern adjustment.

The patent replaces the direct optical-mechanical interaction (laser beam directly modifying the mask through thermal expansion or ablation) with a chemical process. By using laser-induced thermal energy to drive chemical etching reactions in the liquid film, the system achieves pattern adjustment through chemical means rather than direct physical or optical-mechanical means, making it applicable to EUV masks.

The patent performs preliminary actions by forming a liquid film on the mask surface before laser irradiation. This liquid film serves as a removable intermediate layer that enables selective chemical etching. The preliminary formation of this film allows subsequent pattern adjustment through controlled chemical reactions, providing a cost-effective alternative to complete mask replacement while achieving precise critical dimension control.

The patent changes the physical and chemical parameters of the mask surface by introducing a liquid film with specific chemical properties. This parameter change enables selective chemical etching at controlled rates, allowing precise adjustment of critical dimensions. By manipulating chemical concentration, temperature, and exposure time parameters, the system achieves accurate pattern modification without the high cost of remanufacturing entire masks.

The patent integrates multiple functions into a unified system. The liquid film formation system serves dual purposes: it prepares the mask surface for laser irradiation and provides the chemical medium for pattern adjustment. The same apparatus infrastructure (chambers, delivery systems, control mechanisms) handles both liquid film formation and subsequent laser processing, reducing overall system complexity despite the added chemical processing capability.

The patent merges the liquid film formation process with the laser irradiation process into a single integrated treatment chamber. Both functions share common infrastructure including positioning systems, control mechanisms, and safety protocols. By combining these processes spatially and operationally, the system achieves precise pattern adjustment while minimizing the increase in device complexity through shared resources and coordinated operation.