LFLE Double Patterning with Inline CD Slimming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional double patterning techniques, such as LFLE, face limitations in achieving smaller feature sizes due to constraints in the ultimate printable feature size.
Innovation Solution
The method involves a Litho/Freeze/Litho/Etch (LFLE) technique with a first and second critical dimension (CD) slimming process to reduce the CD of patterns in radiation-sensitive material layers, followed by a freeze process to preserve the patterns, allowing for the formation of smaller features by repeating lithographic and etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional LFLE double patterning technique is used, then the patterning process can be completed with standard lithographic techniques, but the ultimate printable feature size is limited and cannot achieve smaller feature sizes
Solution Approach 1:
The patent segments the patterning process into multiple distinct stages: first lithography, freeze treatment, second lithography, and etching. This segmentation allows each stage to be optimized independently, with the freeze stage preserving the first pattern while enabling second pattern formation, ultimately achieving sub-20nm features that would be impossible in a single lithography step
Solution Approach 2:
The freeze treatment is applied as a preliminary action between the two lithography steps. This preliminary freezing of the first pattern in the radiation-sensitive material allows the material to withstand subsequent processing and enables the formation of the second pattern at the same location, effectively preparing the substrate for achieving smaller feature sizes
2Manufacturing precision
If multiple lithography and etching steps are performed to reduce feature size, then smaller features can be achieved, but the process complexity increases
Solution Approach 1:
The patent merges the first and second patterns into the same radiation-sensitive material layer, rather than using separate layers. This merging approach, combined with the freeze treatment, allows both patterns to coexist and be processed together in subsequent etching steps, reducing the overall process complexity compared to using multiple separate lithography layers
3Productivity
If conventional single lithography is used, then the process is simple and fast, but the achievable feature size is larger than desired
Solution Approach 1:
The patent changes the physical and chemical parameters of the radiation-sensitive material through the freeze treatment. This parameter change allows the material to maintain the first pattern while becoming receptive to the second pattern, enabling sub-20nm feature formation without significantly increasing process time or complexity
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 enables the creation of line patterns with critical dimensions less than 20 nm, overcoming the limitations of conventional techniques by achieving smaller feature sizes and improving substrate throughput while reducing defectivity.
Implementation Method 1
freezing the first pattern with the first reduced CD in the first layer of radiation-sensitive material using a freeze process
Data Source
AI summary
A method for double patterning a substrate is described. The double patterning method may include a litho/freeze/litho/etch (LFLE) technique that includes a first (critical dimension) CD slimming process to reduce the first CD to a first reduced CD and a second CD slimming process to reduce the second CD to a second reduced CD.