Fluorine-Passivated Reticles Prevent Material Migration

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Solution Overview

Problem

Conventional photolithography reticles experience material migration when exposed to short-wavelength ultraviolet radiation, leading to distorted features and increased manufacturing costs due to the need for frequent cleaning and replacement.

Innovation Solution

A fluorine-passivated reticle is developed, featuring a substrate with a patterned fluorine-passivated absorber material layer that minimizes material migration by using fluorination processes such as direct, photochemical, thermal, or electrochemical fluorination, maintaining the original dimensions and optical properties of the absorber material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional reticles are used with short-wavelength radiation, then lithographic resolution is improved, but material migration occurs causing feature distortion

Engineering Contradiction:

Improvelithographic resolutionVSAvoidfeature dimension accuracy

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The reticle undergoes preliminary fluorination treatment during fabrication to saturate reactive sites on the absorber material surface. This advance preparation prevents material migration during subsequent lithographic exposure to short-wavelength radiation, allowing high resolution without feature distortion

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The chemical state of the absorber material surface is changed by introducing fluorine atoms, which alters the surface energy and bonding characteristics. This parameter change prevents material migration while maintaining the optical properties needed for short-wavelength lithography

Inventive Principle:

Principle #35Parameter changes

2Reliability

If reticles are cleaned frequently to remove migrated material, then image quality is maintained, but manufacturing costs and downtime increase

Engineering Contradiction:

Improveimage qualityVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The fluorination process is performed in advance during reticle fabrication to prevent material migration before it occurs during lithographic use. This eliminates the need for frequent cleaning operations, maintaining image quality while avoiding production downtime and additional costs

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If absorber material is used without fluorine passivation, then reticle fabrication is simpler, but material migration occurs during exposure

Engineering Contradiction:

Improvereticle fabrication simplicityVSAvoidabsorber material stability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

Fluorine passivation is incorporated as a preliminary step in the reticle fabrication process. This advance treatment stabilizes the absorber material composition by saturating reactive sites, preventing material migration during exposure while adding only one additional process step

Inventive Principle:

Principle #10Preliminary action

4Reliability

If reticles are replaced frequently due to material migration, then image quality is maintained, but costs increase

Engineering Contradiction:

Improveimage qualityVSAvoidreticle lifespan

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The fluorination treatment is applied during initial reticle fabrication to prevent material migration throughout the reticle's service life. This extends reticle lifespan by eliminating the degradation mechanism, reducing replacement frequency while maintaining image quality

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The chemical composition of the absorber material is modified through fluorine incorporation, changing its stability characteristics. This parameter change prevents material migration and extends reticle operational life without sacrificing optical performance

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

The fluorine-passivated reticles prevent material migration during exposure to short-wavelength radiation, allowing for extended use without the need for frequent cleaning or replacement, thereby reducing costs and maintaining image quality.

Implementation Method 1

using fluorination processes such as direct, photochemical, thermal, or electrochemical fluorination

Methodology Applied

Scientific EffectFluorination: Chemical Bonding

Data Source

PatentUS8338061B2Fluorine-passivated reticles for use in lithography and methods for fabricating the same

Publication Date: 2012.12.25 ADVANCED MICRO DEVICES INC

AI summary

Fluorine-passivated reticles for use in lithography and methods for fabricating and using such reticles are provided. According to one embodiment, a method for performing photolithography comprises placing a fluorine-passivated reticle between an illumination source and a target semiconductor wafer and causing electromagnetic radiation to pass from the illumination source through the fluorine-passivated reticle to the target semiconductor wafer. In another embodiment, a fluorine-passivated reticle comprises a substrate and a patterned fluorine-passivated absorber material layer overlying the substrate. According to another embodiment, a method for fabricating a reticle for use in photolithography comprises providing a substrate and forming a fluorine-passivated absorber material layer overlying the substrate.