Semiconductor Fine Pattern Formation via Solubility-Differentiated Double Patterning
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Solution Overview
Problem
The existing methods for forming fine patterns in semiconductor devices face challenges due to the resolution limit of photolithography, requiring expensive deposition equipment and complex processes, especially when forming patterns with high aspect ratios and small pitches.
Innovation Solution
A method using a double patterning process where etch mask patterns are formed with doubled density through a chemical reaction, utilizing capping films and a second mask layer with different solubilities in a solvent to achieve fine pattern formation without expensive deposition equipment, involving the use of heterocyclic compounds and alkali aqueous solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography is used to form fine patterns, then manufacturing process is simple, but resolution limit prevents formation of desired fine-pitch patterns
Solution Approach 1:
The patent divides the pattern formation process into two separate exposure steps: first forming sparse mandrel patterns at a relaxed pitch, then forming additional patterns in the spaces between mandrels. This segmentation allows each exposure step to operate within the resolution capabilities of conventional photolithography while achieving overall finer pitch patterns that would be impossible in a single exposure step.
2Manufacturing precision
If double patterning process with deposition and etching is used, then fine pitch patterns can be formed, but process complexity increases
Solution Approach 1:
The patent extracts and eliminates the deposition step from the conventional double patterning process. Instead of depositing additional material layers to define patterns, the invention uses only photolithographic exposure and development steps with solubility-differentiated resists, thereby reducing process complexity while maintaining fine pitch pattern formation capability.
3Manufacturing precision
If double patterning process with etching is used, then fine pitch patterns can be formed, but manufacturing cost increases
Solution Approach 1:
The patent employs disposable mandrel patterns made from a first resist material that are intentionally designed to be temporary and removable. These mandrels serve only to define the initial pattern framework and are subsequently eliminated through selective dissolution, allowing the formation of final fine pitch patterns without requiring expensive etching equipment or complex process steps.
4Manufacturing precision
If deposition equipment is used for double patterning, then fine patterns can be formed, but equipment cost increases
Solution Approach 1:
The patent replaces the mechanical deposition system with a chemical dissolution system. Instead of using deposition equipment to add material layers for pattern definition, the invention uses chemical differences in resist solubility to selectively remove material and define patterns through development processes, thereby eliminating the need for expensive deposition equipment.
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 reduced manufacturing costs and complexity, enabling the creation of fine-pitch patterns by increasing the density of etch mask patterns and controlling the width of second mask patterns using solvent-based processes.
Implementation Method 1
The plurality of capping films may be attached to the surface of the plurality of first mask patterns by ionic bonds between hydrogen atoms exposed on the surface of the plurality of first mask patterns and nitrogen atoms of the plurality of capping films in the forming of the plurality of capping films.
Implementation Method 2
forming a plurality of capping films formed of a first material having a first solubility in a solvent on sidewalls and a top surface of the plurality of first mask patterns... forming a second mask layer formed of a second material having a second solubility in the solvent, which is less than the first solubility
Data Source
AI summary
A method of forming fine patterns of a semiconductor device includes forming a plurality of first mask patterns on a substrate such that the plurality of first mask patterns are separated from one another by a space located therebetween, in a direction parallel to a main surface of the substrate, forming a plurality of capping films formed of a first material having a first solubility in a solvent on sidewalls and a top surface of the plurality of first mask patterns. The method further includes forming a second mask layer formed of a second material having a second solubility in the solvent, which is less than the first solubility, so as to fill the space located between the plurality of first mask patterns, and forming a plurality of second mask patterns corresponding to residual portions of the second mask layer which remain in the space located between the plurality of first mask patterns, after removing the plurality of capping films and a portion of the second mask layer using the solvent.