Asymmetric Binary Exposure Mask for Curved Surface Profiles

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Solution Overview

Problem

Existing methods for forming pattern profiles with curved surfaces using multiple exposure masks and gradation masks are time-consuming and costly due to the need for repeated lithography and etching processes.

Innovation Solution

A binary exposure mask with asymmetrically arranged pattern blocks, each comprising pattern units with varying shapes and materials, allowing for one-time lithography and etching fabrication, thereby simplifying the process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple exposure masks are used to form pattern profiles with curved surfaces, then the desired complex patterns can be achieved, but the processing time and overall cost increase significantly

Engineering Contradiction:
Improvepattern profile complexityVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The exposure mask is divided into multiple pattern blocks, each containing pattern units with different transmission characteristics. This segmentation allows complex curved surface patterns to be formed in a single exposure step by combining multiple pattern elements on one mask, eliminating the need for multiple sequential exposures while maintaining the ability to create complex three-dimensional photoresist profiles

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from traditional two-dimensional planar masks to three-dimensional pattern blocks with varying light transmission depths. By introducing the depth dimension through different thicknesses of light-blocking layers, the mask can encode multiple pattern layers and curved surface information simultaneously, enabling complex 3D pattern formation in a single exposure step

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If gradation mask method is used to form pattern profiles with curved surfaces, then the light transmission can be controlled, but more fabrication steps are required to create the light-blocking layer with different thicknesses

Engineering Contradiction:
Improvelight transmission controlVSAvoidfabrication process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mask structure is segmented into distinct pattern blocks, each containing light-blocking layers of specific thicknesses arranged in asymmetric configurations. This segmentation provides controllable light transmission for different pattern regions while maintaining a relatively simple single-step lithography and etching fabrication process, avoiding the need for repeated fabrication steps required by traditional gradation masks

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If traditional symmetric arrangement of pattern units is used, then the fabrication process is simpler, but the ability to form complex curved surface profiles is limited

Engineering Contradiction:
Improvefabrication simplicityVSAvoidcurved surface profile accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs asymmetric arrangement of pattern units within pattern blocks, where the spatial configuration and light-blocking layer thicknesses are deliberately made non-uniform. This asymmetry enables precise control over light transmission patterns, allowing accurate formation of complex curved surface profiles while still being achievable through standard single-step lithography and etching processes

Inventive Principle:
Principle #4Asymmetry

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

Reduces processing time and overall cost by eliminating the need for repetitive fabrication steps while effectively forming complex pattern profiles with curved surfaces.

Implementation Method 1

the amount of light transmission depends on the thickness of the light-blocking layer on the (gradation) exposure mask

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Data Source

PatentEP4040232B1Exposure mask
Publication Date: 2025.10.29 VISERA TECH CO LTD
  • EP4040232B1 patent drawingFigure 1
  • EP4040232B1 patent drawingFigure 2
  • EP4040232B1 patent drawingFigure 3A~3G

AI summary

An exposure mask is provided. The exposure mask includes a plurality of pattern blocks for defining a plurality of pattern profiles. Each pattern block includes a plurality of pattern units having mask patterns, and the mask patterns are formed in an asymmetric arrangement. The exposure mask may be a binary exposure mask for forming pattern profiles with curved surfaces.