Directional Etching for Semiconductor Pattern Fidelity

The patent applies preliminary action by performing corner sharpening etching operations before the final patterning steps. The method forms initial patterns with rounded corners, then selectively sharpens the corners through controlled etching, and finally forms the precise final pattern. This preliminary corner treatment ensures that subsequent lithography and etching processes maintain pattern fidelity without corner rounding issues.

The patent segments the patterning process into distinct stages: initial pattern formation, corner sharpening, and final pattern formation. By dividing the continuous patterning workflow into separate operational steps, each optimized for its specific function, the method achieves both manufacturing efficiency and pattern fidelity. The corner sharpening step is isolated as a discrete operation that can be independently controlled and optimized.

The patent applies local quality by selectively treating only the corner regions of patterns rather than the entire pattern structure. The corner sharpening etching is localized to corner portions, applying different etching conditions and durations specifically to corners while leaving other pattern regions unaffected. This localized approach maintains critical dimension control at scaled dimensions while preserving overall pattern integrity.

The patent utilizes parameter changes by varying etching duration, power, and gas flow rates during the corner sharpening process. Different etching parameters are applied to corner regions versus other pattern regions, with corners receiving extended etching exposure to achieve sharp angles while maintaining appropriate dimensions for scaled features. These dynamic parameter adjustments enable precise control at smaller process nodes.

The patent applies the another dimension principle by transitioning from conventional single-direction (vertical) etching to multi-directional etching approaches. The method incorporates angled or slanted etching directions in addition to vertical etching, creating corner regions through the intersection of etched surfaces from different directions. This multi-dimensional approach achieves sharp corner geometry that cannot be obtained through single-direction etching alone.

The patent implements periodic action by applying alternating etching steps with different directions and parameters. The process cycles between vertical etching and angled etching operations, with each cycle refining the corner geometry further. This periodic application of different etching modes allows progressive corner sharpening while maintaining control over the overall pattern dimensions and simplicity of the manufacturing process.