Multi-Wavelength Exposure for Uniform Deep Resist Patterning

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Solution Overview

Problem

Existing lithography processes struggle to form patterns with high aspect ratios and small inclinations in photosensitive material layers on substrates, particularly due to issues with axial and magnification chromatic aberrations and intensity attenuation.

Innovation Solution

An exposure method and device that utilize multiple light sources with different peak wavelengths, adjusting the intensity and emission timing of each light beam to compensate for chromatic aberrations and intensity loss, forming a combined pattern image with uniform intensity across the depth of the photosensitive material layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple light sources with different wavelengths are used to expose through the photosensitive material layer, then the pattern formation capability is improved, but the system complexity increases

Engineering Contradiction:

Improvepattern formation capabilityVSAvoidsystem complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The exposure process is segmented into multiple sequential steps, each using a different wavelength of light. The photosensitive material layer is divided into multiple regions that are exposed at different times with different wavelengths, allowing complex patterns to be formed by combining simpler exposure steps.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the intensity and timing of multiple light sources based on the depth and material properties of the photosensitive layer. The exposure parameters are varied in real-time to optimize pattern formation at different depths while managing system complexity.

Inventive Principle:

Principle #15Dynamics

2Length of stationary object

If the intensity of exposure light is increased to penetrate deeper into the photosensitive material layer, then the exposure depth is improved, but the uniformity of intensity distribution deteriorates

Engineering Contradiction:

Improveexposure depthVSAvoiduniformity of intensity distribution

Core Design Contradiction:

Length of stationary objectVSManufacturing precision

Solution Approach 1:

Different wavelengths of light are assigned to expose different depth regions of the photosensitive material layer. Shorter wavelengths are used for shallower regions while longer wavelengths penetrate deeper, creating a locally optimized exposure strategy that maintains uniformity across the entire depth range.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes the wavelength parameter of the exposure light to control penetration depth and intensity distribution. By selecting appropriate wavelengths from a multi-wavelength light source, the system optimizes both exposure depth and intensity uniformity for each specific exposure step.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If sequential exposure with different wavelengths is performed to achieve uniform intensity distribution, then the intensity uniformity is improved, but the exposure time increases

Engineering Contradiction:

Improveintensity uniformityVSAvoidexposure time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The exposure process uses periodic alternation between different wavelength exposures in a systematic sequence. This periodic application of different wavelengths allows the system to achieve uniform intensity distribution while maintaining a controlled and efficient exposure timeline.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The multi-wavelength exposure process is designed to be continuous, with each wavelength exposure step immediately following the previous one without idle time. This continuous sequential exposure maintains high productivity while achieving the desired intensity uniformity through the coordinated use of multiple wavelengths.

Inventive Principle:

Principle #20Continuity of useful action

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

The method and device enable the formation of patterns with high aspect ratios and uniform intensity distribution, addressing the challenges of chromatic aberrations and intensity attenuation, resulting in improved pattern quality.

Implementation Method 1

illuminating a first object with exposure light including first exposure light having a first peak wavelength and second exposure light having a second peak wavelength... the intensity of the second exposure light with which the second object is irradiated is set to be higher than the intensity of the first exposure light

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS20250341783A1Exposure method, exposure device, and device manufacturing method

Publication Date: 2025.11.06 NIKON CORP

AI summary

An exposure method includes illuminating a first object with exposure light including first exposure light having a first peak wavelength and second exposure light having a second peak wavelength, the second peak wavelength being different from the first peak wavelength, and exposing a second object with the exposure light from the first object, wherein a ratio between an intensity of the second exposure light with which the second object is irradiated and an intensity of the first exposure light with which the second object is irradiated is variable, and the intensity of the second exposure light with which the second object is irradiated is set to be higher than the intensity of the first exposure light with which the second object is irradiated.