Photo-nanoimprinting Reversal Layer for High Aspect Ratio Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photo-nanoimprinting faces challenges in achieving high dry etching resistance for the concavo-convex patterned resist film, requiring a high dry etching rate for the reversal layer while maintaining pattern accuracy and minimizing release defects, especially with larger pattern heights.
Innovation Solution
A method involving a photocurable composition with a polymerizable compound and photopolymerization initiator, where the mold contact step is performed in a soluble gas atmosphere, enhancing the dry etching rate and reducing release defects by using a reversal layer to expose convexes and etch the concavo-convex pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cured film is used as an etching mask with high dry etching resistance, then the etching precision is improved, but the mold-releasing step becomes difficult and release defects increase
Solution Approach 1:
The patent introduces a reversal layer as an intermediary between the mold and the cured film. This reversal layer serves as the actual etching mask, while the cured film's primary function becomes mold release. The reversal layer can be easily removed after etching, solving the contradiction between needing high etching resistance and easy mold release.
Solution Approach 2:
The patent divides the single functional layer (cured film) into two separate layers: the cured film layer and the reversal layer. Each layer is optimized for its specific function - the cured film for mold release and the reversal layer for etching mask functionality, thereby resolving the conflicting requirements.
2Manufacturing precision
If the concavo-convex pattern has a large pattern height to ensure precision, then the pattern definition is improved, but release defects increase during mold-releasing step
Solution Approach 1:
The reversal layer acts as a mediator that allows the mold to be released from the cured film without directly interacting with the deep concavo-convex patterns. The mold releases from the cured film surface, while the reversal layer remains in the patterns, eliminating the direct release conflict that causes defects in high-aspect-ratio structures.
Solution Approach 2:
Instead of using the cured film itself as the etching mask (direct approach), the patent inverts the approach by forming a reversal layer on the cured film and using that as the etching mask. This inversion allows the cured film to be optimized for mold release while the reversal layer provides the etching mask function.
3Productivity
If the cured film layer is quickly removed to enable reversal process, then the productivity is improved, but the etching mask function is compromised
Solution Approach 1:
The patent extracts the etching mask function from the cured film and assigns it to a separate reversal layer. This allows the cured film to be quickly removed (or the reversal layer to be selectively removed) without compromising the etching mask function, as the reversal layer maintains this function until the etching process is complete.
Solution Approach 2:
By segmenting the functions into separate layers, the patent allows independent optimization of removal characteristics. The reversal layer can be designed for easy removal after etching, while the cured film can be optimized for other functions, thereby improving overall productivity without sacrificing etching precision.
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 allows for high processing accuracy and reduced defects in forming fine patterns, even with smaller mold pattern heights, by increasing the dry etching rate and improving the release process.
Implementation Method 1
a photopolymerization initiator which generates radicals by light irradiation
Implementation Method 2
a soluble gas-filling step of dissolving a soluble gas in the photocurable composition and photocuring the composition in such a state
Data Source
AI summary
Method of forming a pattern by arranging a photocurable composition on a substrate; bringing a mold having a concavo-convex pattern into contact with the composition; irradiating the composition with light to form a cured film; releasing the mold from the cured film; forming a reversal layer on the cured film having a concavo-convex pattern transferred from the mold; partially removing the reversal layer to expose the convexes of the pattern in such a manner that the reversal layer remains in the concaves of the pattern formed on the cured film; and etching the photocurable composition layer using the reversal layer remaining in the concaves as a mask to form a reversal pattern, wherein the mold is brought into contact with the photocurable composition in an atmosphere of a soluble gas having a solubility in the composition; and the soluble gas has a saturation solubility of 38% by volume or more.