Rectangular Mold-Forming Substrate Flatness and Parallelism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In nanoimprint lithography, achieving high flatness and parallelism in mold-forming substrates is crucial for precise pattern transfer, but existing substrates often suffer from misalignment and pressure uniformity issues due to larger outer shapes compared to pattern-forming regions, leading to pattern errors and reduced accuracy.

Innovation Solution

A rectangular mold-forming substrate with a central region of 1 to 50 mm by 1 to 50 mm having a flatness of up to 350 nm and a birefringence of up to 3 nm/cm, where the distance between the central region and the peripheral region is greater than or equal to the peripheral region's distance from the opposing surface, ensuring uniform pressure and parallelism during pattern transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the outer shape of the mold-forming substrate is made larger to match traditional lithography substrate sizes, then compatibility with existing equipment and economic feasibility are improved, but the flatness of the pattern-forming region deteriorates leading to misalignment and pattern errors

Engineering Contradiction:
Improvecompatibility with existing equipmentVSAvoidflatness of pattern-forming region
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The substrate is divided into two distinct regions: a large outer shape region for equipment compatibility and a smaller central pattern-forming region for high precision. This segmentation allows each region to serve its specific function independently, resolving the contradiction between size compatibility and pattern precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are given different quality characteristics. The central region is specifically engineered with superior flatness (≤350 nm) and lower birefringence (≤3 nm/cm) compared to the peripheral regions, allowing high precision pattern formation while maintaining overall substrate compatibility with existing equipment.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the pattern-forming region is made smaller to improve flatness and parallelism accuracy, then pattern transfer precision is improved, but the outer shape size remains large causing pressure uniformity issues

Engineering Contradiction:
Improveparallelism accuracyVSAvoidpressure uniformity
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The substrate exhibits local quality differentiation where the central pattern-forming region has optimized flatness and parallelism properties, while the peripheral regions can have different characteristics. This allows the small central region to achieve high precision without being constrained by the larger outer dimensions that affect pressure distribution.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

By separating the pattern-forming function (central region) from the structural support function (peripheral regions), the invention allows independent optimization of each region's properties, enabling high parallelism accuracy in the pattern region while managing pressure uniformity through the overall substrate structure.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If the flatness of the central region is increased to reduce misalignment, then pattern transfer accuracy is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improvepattern transfer accuracyVSAvoidsubstrate manufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

High flatness (≤350 nm) and low birefringence (≤3 nm/cm) are applied locally only to the central pattern-forming region rather than the entire substrate. This localized quality enhancement achieves the necessary pattern transfer accuracy while minimizing manufacturing complexity and cost compared to processing the whole substrate to the same precision level.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2728406B1Rectangular mold-forming substrate
Publication Date: 2020.09.30 SHIN ETSU CHEMICAL CO LTD
  • EP2728406B1 patent drawingFigure 1
  • EP2728406B1 patent drawingFigure 2A~2B
  • EP2728406B1 patent drawingFigure 3A~3B

AI summary

A rectangular substrate is used as a mold after it is provided with a topological pattern. The substrate has A-side and B-side opposed surfaces, the A-side surface being provided with the topological pattern. The A-side surface includes a central rectangular region of 1 to 50 mm by 1 to 50 mm having a flatness of up to 350 nm. Use of the mold-forming substrate prevents the occurrence of a pattern misalignment or pattern error between the step of forming a pattern on a mold-forming substrate and the transfer step. Transfer of a fine size and complex pattern is possible.