Imprint Mold Deformation for Overlay Error Reduction
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Solution Overview
Problem
The imprint technique faces challenges in accurately transferring nanoscale micropatterns due to limited mold correction methods, leading to overlay accuracy issues when forming patterns on substrates, especially when dealing with multiple shot regions or entire surface patterns.
Innovation Solution
A method that involves forming a first pattern on a substrate, followed by an imprint process where the mold is deformed to correct shape discrepancies, allowing the formation of a second pattern with reduced overlay errors by using a controller to align and deform the mold based on detected positional and shape deviations between mold-side and substrate-side marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the imprint process is performed at once in a plurality of shot regions or shot regions on the entire surface of a substrate, then productivity is improved, but overlay accuracy deteriorates because the shapes of patterns formed in respective shot regions are different and correction is difficult
Solution Approach 1:
The substrate surface is divided into multiple shot regions, and the imprint process is performed separately for each shot region rather than simultaneously across the entire substrate. This segmentation allows for individual correction of pattern shapes in each shot region, maintaining overlay accuracy while still achieving high productivity through systematic processing of multiple regions.
Solution Approach 2:
The pattern shape of the mold is corrected in advance before the imprint process is performed. By preliminarily adjusting the mold pattern shape to match the target pattern shape on the substrate, the invention ensures that overlay accuracy is maintained from the beginning of the imprint process, preventing the need for complex real-time corrections during multi-shot region processing.
2Manufacturing precision
If the mold correction mechanism is used to correct the pattern shape of a mold, then manufacturing precision is improved, but device complexity increases and correction capability is limited
Solution Approach 1:
The invention replaces complex mechanical mold correction mechanisms with a computational approach. A calculator computes the necessary correction amounts based on the difference between the actual mold pattern shape and the target pattern shape, and this computational correction information is then applied to adjust the imprint process parameters, thereby achieving high precision without complex mechanical correction systems.
Solution Approach 2:
The invention changes the parameters of the imprint process based on computed correction amounts. Instead of physically deforming the mold through complex mechanisms, the process parameters such as imprint pressure, temperature, or alignment are adjusted according to the calculated correction values, achieving pattern shape correction through parameter optimization rather than mechanical modification.
3Manufacturing precision
If the mold pattern is pressed against the substrate via resin and the substrate is irradiated with ultraviolet rays to cure the resin, then manufacturing precision is improved, but the mold may be deformed during the imprint steps leading to overlay errors
Solution Approach 1:
The mold pattern shape is corrected in advance before the imprint process begins. By preliminarily adjusting the mold pattern to account for expected deformations during the imprint process, the invention compensates for shape changes that occur during resin filling and curing, ensuring that the final transferred pattern maintains high overlay accuracy despite mold deformation during processing.
Solution Approach 2:
The invention implements a feedback mechanism where the actual mold pattern shape is measured and compared with the target pattern shape, and correction amounts are computed based on this comparison. This feedback loop allows for continuous adjustment and compensation of mold deformations that occur during the imprint process, maintaining pattern transfer accuracy throughout the manufacturing sequence.
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 enhances overlay accuracy by allowing real-time correction of mold shape deviations, ensuring that the overlay error between initial and final patterns falls within an acceptable range, thereby improving the precision of pattern transfer in mass production of magnetic storage media and semiconductor devices.
Implementation Method 1
the second shot arrangement is defined so as to reduce an overlay error between the first shot arrangement and the second shot arrangement by deforming the mold
Implementation Method 2
the substrate is irradiated with ultraviolet rays, thereby curing the resin
Data Source
AI summary
A pattern forming method includes: a first step of forming a first pattern to define a first shot arrangement; and a second step of performing an imprint process, thereby forming a second pattern on the imprint material on the first pattern and defining a second shot arrangement. In the second step, the second shot arrangement is defined so as to reduce an overlay error between the first and second shot arrangements by deforming the mold. In the first step, based on information of the estimated second shot arrangement definable on the substrate when the second step is performed after the second pattern formed on the mold is amended by deforming the mold, the first pattern is formed to make an overlay error between the first and second shot arrangements fall within an allowable range.