Hard Mask Opening Expansion for Pattern Fidelity at Concave Corners
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Solution Overview
Problem
Pattern corner rounding during photolithography and etching processes in semiconductor manufacturing leads to reduced process window and pattern fidelity, particularly in smaller process nodes.
Innovation Solution
A method involving directional etching to transform target patterns with concave corners into hole-type patterns free of concave corners, thereby maintaining design margins and enhancing pattern fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithography and etching processes are used, then manufacturing process is simple, but pattern corner rounding occurs reducing pattern fidelity
Solution Approach 1:
The patent segments the pattern formation process into multiple steps: forming initial patterns with first material, performing directional etching to create openings, then forming second material in the openings. This segmentation allows each step to optimize for its specific function, preventing corner rounding while maintaining manufacturability.
Solution Approach 2:
The patent performs preliminary actions by forming the first material pattern and directional etching openings before finalizing the critical structures. This preliminary structuring creates a framework that guides subsequent processing and prevents corner rounding in the final pattern.
2Productivity
If geometry size is decreased to increase functional density, then production efficiency increases, but pattern corner rounding becomes more prominent
Solution Approach 1:
The patent applies local quality by using directional etching that selectively modifies specific regions (creating vertical sidewalls in openings) while leaving other regions unchanged. This localized processing maintains precision at critical dimensions without requiring global process changes, enabling scaling to smaller nodes.
Solution Approach 2:
The patent transitions from planar pattern formation to three-dimensional structuring by creating openings with vertical sidewalls through directional etching. This dimensional change allows patterns to maintain fidelity at smaller scales by utilizing the third dimension for structural definition.
3Reliability
If right angles in design pattern are maintained through conventional processes, then design intent is preserved, but process window decreases due to corner rounding
Solution Approach 1:
The patent replaces conventional isotropic etching mechanics with directional etching mechanics that use controlled ion bombardment angles. This substitution creates anisotropic etching profiles with vertical sidewalls, expanding the process window by making the pattern formation less sensitive to conventional corner rounding effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively reduces concave corner rounding, maintaining design margins and enhancing pattern fidelity, thus improving the process window and overall semiconductor manufacturing efficiency.
Implementation Method 1
applying a directional etching to expand the at least one opening in a first direction
Implementation Method 2
applying a directional etching to expand the at least one opening
Data Source
AI summary
The present disclosure provides a method for semiconductor manufacturing in accordance with some embodiments. The method includes forming a hard mask layer over a substrate, the substrate having one or more regions to receive a treatment process, forming a resist layer over the hard mask layer, patterning the resist layer to form a plurality of openings in the resist layer, each of the openings free of concave corners, performing an opening expanding process to enlarge at least one of the openings in the resist layer, transferring the openings in the resist layer to the hard mask layer, and performing the treatment process to the one or more regions in the substrate through the openings in the hard mask layer.