Projection Lens Assembly Electrode Structural Integrity

The patent uses composite material construction where electrodes are made of thin metal layers (e.g., aluminum or copper foil) bonded to rigid support substrates (e.g., ceramic or metal plates). This composite structure maintains the electrostatic field stability of thin electrodes while providing the mechanical strength and rigidity of the support substrate, preventing electrode deformation and damage during handling and operation.

The patent introduces rigid support substrates as intermediary elements between the thin electrodes and the mechanical stresses they encounter. These substrates act as mediators that distribute mechanical loads away from the fragile thin electrodes, providing structural reinforcement without interfering with the electrostatic field generation function of the thin electrode layers.

The patent designs lens assemblies where a single electrode structure performs multiple functions: it generates the primary electrostatic field for beam focusing while simultaneously providing aberration correction through specifically shaped field regions. This multi-functionality eliminates the need for separate correction electrodes, reducing overall assembly complexity while maintaining correction capability.

The patent implements local quality variations in the electrode design, where different regions of the same electrode have different geometries or potentials optimized for specific functions. For example, central regions may be optimized for focusing while peripheral regions provide astigmatism correction, allowing a single electrode to deliver both focusing and correction functions with appropriate local optimizations.

The patent introduces insulating spacers and support substrates as intermediary elements between closely spaced electrodes. These intermediaries maintain the small distances required for stable electrostatic fields while providing electrical insulation that prevents spark discharge, allowing the system to operate reliably with closely spaced electrodes.

The patent converts the potentially harmful effect of high electric field intensity (which causes sparks) into a beneficial feature by using the strong field for improved focusing precision. Through careful electrode geometry design and insulation, the high field regions are confined to where they provide benefit for beam control, while insulation structures prevent breakdown in critical areas.

The patent segments the electrode assembly into modular units that can be independently replaced. When one electrode or a small group of electrodes becomes damaged, only that specific module needs to be replaced rather than the entire assembly, minimizing downtime and maintaining high productivity while preserving system reliability.

The patent implements preliminary design features such as pre-assembled electrode modules with integrated support structures and connection interfaces. These modules are prepared in advance and can be quickly swapped into the system, reducing the time required for electrode replacement and minimizing disruption to lithography productivity.