Dual-Exposure Photolithography for Lower EUV Dose Patterning

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Solution Overview

Problem

EUV lithography is an expensive process in semiconductor manufacturing, requiring high energy doses that increase costs and equipment expenses, limiting its widespread adoption.

Innovation Solution

Employing a dual-dose exposure method using both UV and EUV light to sensitize the photoresist, reducing the EUV light dose needed for patterning by altering the solubility characteristics of the photoresist, thereby lowering energy and equipment costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If EUV lithography is used for photolithography, then manufacturing precision is improved, but use of energy increases and device complexity increases

Engineering Contradiction:

Improvecritical dimensionVSAvoidEUV light dose

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary UV exposure to the photoresist before EUV exposure to sensitize the photoresist material. This preliminary action modifies the photoresist's solubility characteristics, making it more responsive to subsequent EUV exposure and enabling reduced EUV doses while maintaining patterning quality and critical dimension precision.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If EUV lithography is used for photolithography, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improvecritical dimensionVSAvoidequipment cost

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a dual-exposure approach using both UV and EUV light sources to achieve EUV-level patterning precision. By combining UV sensitization with reduced-dose EUV exposure, the method enables high-precision manufacturing using existing UV infrastructure alongside EUV capabilities, thereby reducing equipment complexity and cost while maintaining critical dimension quality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If EUV lithography is used for photolithography, then productivity is improved, but use of energy increases

Engineering Contradiction:

ImprovethroughputVSAvoidEUV light dose

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the photoresist's solubility parameters through preliminary UV exposure, which enables the material to achieve the same patterning effect at lower EUV energy doses. This parameter change in photoresist sensitivity allows reduced EUV dosage while maintaining productivity and throughput, directly addressing the energy consumption issue.

Inventive Principle:

Principle #35Parameter changes

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 EUV light dose by approximately 35-45%, leading to lower manufacturing costs and increased throughput while maintaining critical dimension targets, without the need for specialized resist materials.

Implementation Method 1

expose the photoresist layer to ultraviolet light to sensitize the photoresist layer

Methodology Applied

Scientific EffectPhotochemical sensitization: Photopolymerisation

Data Source

PatentEP4625049A1Methods and apparatus to reduce extreme ultraviolet light for photolithography

Publication Date: 2025.10.01 INTEL CORP

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AI summary

Apparatus and methods are disclosed. An example lithography apparatus includes an ultraviolet (UV) source to expose a photoresist layer to UV light; and an extreme ultraviolet (EUV) source coupled to the UV source, the EUV source to expose the photoresist layer to EUV light to via a photomask, a combination of the UV light and the EUV light provide a pattern on the photoresist layer when a developer solution is applied to the photoresist layer.