Photoresist Capping Layer Acid Diffusion for Fine Pattern Resolution
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Solution Overview
Problem
In the fabrication of ultra-large-scale integrated semiconductor devices, existing technologies face limitations in forming a plurality of fine patterns with a fine pitch in a limited area, as exposure wavelengths are reduced, making it difficult to achieve high integration and resolution.
Innovation Solution
A method involving the formation of a photoresist pattern with a capping layer containing an acid source, where acid is diffused to create an insoluble region, allowing for the etching of the to-be-etched film using the insoluble region as a mask, enabling the formation of fine patterns by selectively removing soluble regions and using the insoluble region to expose additional areas for further etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If exposure wavelength is reduced to increase resolution, then pattern resolution is improved, but manufacturing complexity and process difficulty increase
Solution Approach 1:
The patent segments the pattern formation process into multiple stages: initial photoresist patterning, capping layer formation with acid sources, acid diffusion to create insoluble regions, and selective removal of soluble regions. This segmentation allows each stage to be optimized independently, achieving high resolution without requiring extreme exposure wavelength reduction.
Solution Approach 2:
The patent applies preliminary action by forming capping layers with acid sources on the photoresist pattern before the main etching process. The acid diffuses in advance to create insoluble regions that will serve as etch masks, preparing the structure for subsequent high-precision patterning without requiring more aggressive exposure conditions.
2Productivity
If multiple fine patterns with fine pitch are formed in limited area, then device integration is improved, but exposure and patterning difficulty increase
Solution Approach 1:
The patent introduces capping layers containing acid sources as intermediary structures between the photoresist pattern and the to-be-etched film. These intermediaries facilitate the formation of multiple fine patterns by enabling acid diffusion to create additional insoluble regions, allowing high device integration without directly increasing patterning difficulty.
Solution Approach 2:
The patent applies local quality by creating regions with different solubility characteristics within the photoresist pattern. The acid diffusion process creates localized insoluble regions around specific openings while leaving other regions soluble, enabling selective etching and formation of multiple fine patterns with different properties in the same structure.
3Manufacturing precision
If acid diffusion is used to form insoluble regions, then pattern precision is improved, but process time increases
Solution Approach 1:
The patent utilizes parameter changes by controlling the diffusion of acid through the photoresist pattern. By adjusting acid concentration, diffusion temperature, and time parameters, the process achieves high pattern precision in the acid diffusion step without excessive time consumption, optimizing the trade-off between precision and process time.
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
This method effectively forms fine patterns with high precision, enabling the creation of highly integrated semiconductor devices by overcoming the limitations of reduced exposure wavelengths and increasing resolution in pattern formation.
Implementation Method 1
forming an insoluble region around the first opening in the photoresist pattern by diffusing acid obtained from the acid source from the capping layer to the inside of the photoresist pattern
Implementation Method 2
forming a photoresist pattern on a to-be-etched film by using a composition including a polymer that has a polarity that is changeable by an action of acid; exposing the photoresist film to form a main exposed region, a non-exposed region spaced apart from the main exposed region, and an exposed edge region disposed between the main exposed region and the non-exposed region
Data Source
AI summary
Provided are a method of forming patterns and a method of manufacturing an integrated circuit device. In the method of forming patterns, a photoresist pattern having a first opening exposing a first region of a target layer is formed. A capping layer is formed at sidewalls of the photoresist pattern defining the first opening. An insoluble region is formed around the first opening by diffusing acid from the capping layer to the inside of the photoresist pattern. A second opening exposing a second region of the target layer is formed by removing a soluble region spaced apart from the first opening, with the insoluble region being interposed therebetween. The target layer is etched using the insoluble region as an etch mask.