Substrate Patterning with Dry Resist Development for Line Cuts
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Solution Overview
Problem
Conventional lithography techniques struggle to form closely spaced line cuts on substrates due to pattern collapse and increased defectivity during wet development processes, especially at advanced technology nodes, necessitating complex multi-layer approaches that increase manufacturing costs.
Innovation Solution
A method involving solubility shifting agents that diffuse between resist layers, followed by dry development processes such as thermal treatment, reactive gas exposure, or plasma etching, to form precise patterns without liquid-induced capillary effects, using self-immolative polymers for controlled depolymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wet development processes are used, then photoresist patterns can be formed, but pattern collapse and defectivity increase at advanced technology nodes
Solution Approach 1:
The patent replaces the wet chemical development process with a dry development process using plasma or reactive gas. This substitution eliminates liquid-induced capillary forces that cause pattern collapse, while maintaining the ability to selectively remove exposed or unexposed photoresist material through controlled chemical reactions in the gas phase.
Solution Approach 2:
The patent changes the development mechanism from liquid-based dissolution to solid-gas phase interaction. By using plasma or reactive gas at controlled temperatures and pressures, the development process achieves high precision pattern formation without the mechanical stresses and capillary effects inherent in wet development, thereby improving pattern fidelity and reducing collapse.
2Manufacturing precision
If multi-layer approaches are used to form closely spaced line cuts, then pattern fidelity is maintained, but process complexity and manufacturing costs increase
Solution Approach 1:
The patent segments the development function into two distinct stages: first, the photoacid generator creates localized chemical changes in the photoresist upon exposure; second, the dry development process selectively removes modified regions through plasma or reactive gas treatment. This segmentation allows precise control over pattern formation without requiring additional intermediate layers, simplifying the overall process.
Solution Approach 2:
The patent introduces a photoacid generator as an intermediary substance within the photoresist layer that mediates the transformation from exposed to removable regions. Upon actinic radiation exposure, the photoacid generator produces acid that catalyzes chemical changes in the photoresist, creating distinct solubility differences that enable precise pattern transfer during dry development without needing extra mask or intermediate layers.
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 approach reduces process steps, minimizes pattern collapse, and enhances pattern fidelity by maintaining integrity during advanced semiconductor manufacturing, thereby reducing defectivity and complexity.
Implementation Method 1
diffusing the solubility shifting agent into the second resist layer to form solubility shifted regions in the second resist layer
Implementation Method 2
selectively exposing portions of the first resist layer to actinic radiation through a photomask to activate the photoacid generator
Implementation Method 3
dry development processes such as thermal treatment, reactive gas exposure, or plasma etching
Implementation Method 4
dry development processes such as thermal treatment, reactive gas exposure, or plasma etching
Implementation Method 5
using self-immolative polymers for controlled depolymerization
Data Source
AI summary
A method is provided for processing a substrate. The method includes providing a substrate having a first patterned resist layer disposed over a layer to-be-etched, where the first patterned resist layer includes solubility shifting agent. A second resist layer is disposed over the first patterned resist layer. The solubility shifting agent diffuses into the second resist layer to form solubility shifted regions in the second resist layer. The solubility shifted regions are removed using a dry development process to form a second patterned resist layer. The layer to-be-etched is etched using the first and the second patterned resist layers as a combined etch mask.