Double Patterning Resist Reversal for Fine Pattern Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current double patterning processes for LSI fabrication are complex, requiring multiple lithography and etching steps, and face challenges in achieving fine patterns due to low resolution of negative resist materials and thermal flow limitations, especially in miniaturizing both spaces and isolated lines simultaneously.
Innovation Solution
A double patterning process involving partial crosslinking of a chemically amplified positive resist composition to make it alkali-soluble for reversal transfer, allowing for the formation of fine space patterns through positive/negative reversal using a first and second resist composition, enabling single etching and improved process margins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional double patterning processes are used, then fine patterns can be formed, but the process complexity increases with multiple lithography and etching steps
Solution Approach 1:
The patent combines multiple lithography and etching steps into a simplified double patterning process using two resist compositions. The first positive resist pattern is formed, then a second positive resist composition is coated and exposed to form a reversed pattern through chemical amplification. This merging of steps reduces process complexity while maintaining fine pattern formation capability.
Solution Approach 2:
The patent utilizes chemical amplification parameter changes in the second resist composition to achieve pattern reversal. By controlling the chemical reactions and exposure parameters, the first positive pattern is converted into a reversed pattern that can be etched with a single etching step, thereby simplifying the overall process.
2Length of moving object
If thermal flow is used for miniaturization, then space patterns can be reduced, but isolated lines cannot be miniaturized simultaneously
Solution Approach 1:
The patent segments the patterning process into two distinct lithography steps with two different resist compositions. The first resist forms initial patterns, and the second resist with chemical amplification handles the reversal and miniaturization. This segmentation allows different regions (spaces and isolated lines) to be miniaturized through the same chemical amplification mechanism, achieving versatility that thermal flow cannot provide.
Solution Approach 2:
The patent applies parameter changes through chemical amplification in the second resist composition to miniaturize both space patterns and isolated lines simultaneously. By controlling the chemical reactions and exposure parameters, uniform miniaturization is achieved across different pattern types, overcoming the limitation of thermal flow which only affects space patterns.
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 process simplifies the double patterning technique by allowing for the formation of fine patterns with improved resolution and process margins, enabling the creation of complex patterns like crisscross holes and ultra-fine trench patterns with reduced pitch, while maintaining compatibility for high-density integration and high-speed operation.
Implementation Method 1
a first chemically amplified positive resist composition is coated onto a processable substrate
Implementation Method 2
exposure and development to form a first positive pattern, and heat or otherwise treatment for converting the positive pattern to be alkali soluble
Data Source
AI summary
Double patterns are formed by coating a first chemically amplified positive resist composition comprising an acid labile group-bearing resin and a photoacid generator and prebaking to form a resist film on a processable substrate, exposing the resist film to high-energy radiation, PEB, and developing with an alkaline developer to form a first positive resist pattern, treating the first resist pattern to be alkali soluble and solvent resistant, coating a second resist composition and prebaking to form a reversal film, and exposing the reversal film to high-energy radiation, PEB, and developing with an alkaline developer to form a second positive resist pattern. The last development step includes dissolving away the reversed first resist pattern and achieving reversal transfer.