Cross-Linked Underlayer Structure for Swelling-Resistant Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor IC device manufacturing, the bi-layer and tri-layer structures used in photolithography patterning processes face issues with material penetration into the bottom layer, leading to swelling and stress-induced delamination or deformation, which affects the reproducibility and critical dimensions of patterned features.
Innovation Solution
The bottom layer is modified by incorporating polymers and cross-linking agents, with a higher concentration of cross-linking agents in the upper section to inhibit penetration by etching agents, and the use of specific polymers and cross-linking monomers to enhance the layer's resistance and adhesion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a bottom layer is used in photolithography patterning, then adhesion and structural support are improved, but material penetration into the bottom layer causes swelling and stress-induced delamination
Solution Approach 1:
The patent modifies the bottom layer composition by incorporating cross-linking agents (e.g., glycoluril, melamine, cyanuric acid) that form cross-linked polymer networks. This changes the physical and chemical parameters of the bottom layer, reducing material penetration and swelling while maintaining adhesion to the substrate.
Solution Approach 2:
The bottom layer is formulated as a composite material containing polymer resins (e.g., polyhydroxystyrene, novolac) combined with cross-linking agents. This composite structure provides both adhesion properties and resistance to swelling, resolving the contradiction between maintaining strong bonding and preventing delamination.
2Manufacturing precision
If etching agents are used to remove underlying materials, then patterning precision is improved, but penetration into the bottom layer causes swelling and deformation
Solution Approach 1:
The bottom layer is pre-treated with cross-linking agents before the etching process. This preliminary action creates a cross-linked network that resists penetration by etching agents, preventing swelling and deformation that would otherwise occur during the etching step.
Solution Approach 2:
The chemical structure of the bottom layer is modified through cross-linking, changing its resistance parameters to etching agents. This allows the layer to withstand the etching process while maintaining its shape and dimensional integrity.
3Stability of the object's composition
If the bottom layer is made more resistant to etching agents, then swelling is reduced, but adhesion and cross-linking complexity increase
Solution Approach 1:
The patent employs multiple different cross-linking agents with different functions and properties. Each cross-linking agent targets specific aspects of resistance or adhesion, allowing the bottom layer to achieve comprehensive performance through a tailored combination of materials rather than a single complex substance.
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 modification improves the resistance of the bottom layer to etching agents, reducing swelling and stress, thereby enhancing the reproducibility and accuracy of the lithography patterning process.
Implementation Method 1
The bottom layer is thermally treated to cross-link the polymer with the cross-linking agents
Implementation Method 2
modifying the bottom layer serves to mitigate or remedy this unwanted swelling and the attendant adverse effects of such swelling
Data Source
AI summary
A method includes providing a layered structure on a substrate, the layered structure including a bottom layer formed over the substrate and a photoresist layer formed over the bottom layer, exposing the photoresist layer to a radiation source, developing the photoresist layer, patterning the bottom layer and removing portions of the substrate through openings in the patterned bottom layer. In some embodiments, a middle layer is provided between the bottom layer and the photoresist layer. The material of the bottom layer includes at least one cross-linking agent that has been functionalized to decrease its affinity to other materials in the bottom layer.