Thermally Shrinkable Metal-Oxide Lithography for Sub-193i Resolution
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Solution Overview
Problem
Current methods for reducing critical dimensions in integrated circuits beyond 193i lithography resolution, such as triple Litho-Etch techniques, require multiple amorphous carbon layers and controlled etch processes, which are complex and inefficient.
Innovation Solution
A method involving multiple cycles of lithographical patterning and thermal shrinking of metal-oxide layers, where different metal-oxides with varying etch selectivities are used, allowing for the reduction of feature size without the need for additional amorphous carbon layers or complex etch processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If triple Litho-Etch techniques are used to reduce critical dimensions below 193i lithography resolution, then feature size is reduced, but process complexity increases due to requiring multiple amorphous carbon layers and controlled etch processes
Solution Approach 1:
The patent changes the material parameter from conventional photoresist to thermally shrinkable metal-oxide layers, which undergo phase transition upon heating. This parameter change enables the material to automatically reduce its critical dimension through thermal shrinkage after lithography, eliminating the need for multiple etch-deposition cycles and reducing process complexity while achieving sub-193i resolution features
Solution Approach 2:
The patent exploits the phase transition property of thermally shrinkable metal-oxide materials that transform from a relaxed state to a shrunk state when heated above their transition temperature. This phase transition occurs after lithography patterning, automatically reducing the feature size without requiring additional complex etch processes, thus resolving the contradiction between feature size reduction and process complexity
2Length of moving object
If triple Litho-Etch techniques are used to reduce critical dimensions, then feature size is reduced, but manufacturing steps increase due to requiring three times amorphous carbon layer deposition and etching
Solution Approach 1:
The patent changes the material system to thermally shrinkable metal-oxide layers that can be deposited as a single layer and then shrunk through thermal processing. This parameter change eliminates the need for multiple amorphous carbon layer depositions and etching steps, reducing the number of manufacturing steps from three cycles to one cycle plus thermal shrinkage, thereby improving productivity while achieving the same feature size reduction
Solution Approach 2:
The patent extracts and removes the amorphous carbon layers from the process flow by using thermally shrinkable metal-oxide materials that do not require protective carbon layer coverage. This extraction eliminates unnecessary manufacturing steps and simplifies the overall process, improving manufacturing efficiency while maintaining the ability to produce sub-lithography resolution features
3Ease of manufacture
If standard photolithography is used, then process simplicity is maintained, but feature size cannot be reduced below lithography resolution limits
Solution Approach 1:
The patent applies preliminary lithography patterning to create oversized features that are larger than the final desired critical dimension. After lithography, a thermal shrinkage step is applied to reduce these pre-formed features to the target sub-193i resolution size. This preliminary action approach maintains process simplicity by using standard lithography equipment while achieving feature size reduction through the subsequent thermal shrinkage of metal-oxide 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
Enables the reduction of feature size below standard photolithography limits, simplifying the process and eliminating the need for additional etch-deposition steps, while maintaining control over critical dimensions and pitch, allowing for the creation of smaller than litho-resolution structures.
Implementation Method 1
thermally shrinking the metal-oxide pattern
Data Source
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AI summary
A method (100) for lithographic patterning of a substrate is described. The method comprises obtaining a substrate to be patterned. It furthermore comprises subsequently applying at least twice the following cycle : applying a lithographical patterning process of a thermally shrinkable metal-oxide layer for forming a metal-oxide pattern, and thermally shrinking the metal-oxide pattern. The different metal oxide patterns formed during the at least two cycles are outlined relatively with respect to each other so that the shrunk metal-oxide patterns form together an overall pattern to be transferred to the substrate. After said applying at least twice the cycle, the overall pattern is transferred to the substrate.