Pellicle Film Foreign Matter Removal via VUV and Inert Gas

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Solution Overview

Problem

There is a concern that foreign matter adheres to the pellicle film during the pellicle production process, leading to potential damage due to local hot spots during exposure, which can affect the yield rate of semiconductor production.

Innovation Solution

A foreign matter removing device that uses vacuum ultraviolet (VUV) light and inert gas to prevent foreign matter from adhering to the pellicle film, while also suppressing film breakage and maintaining a low oxygen concentration within the irradiation chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If foreign matter is present on the pellicle film, then the absorption of radiation increases during exposure, but this leads to local hot spots and damage to the pellicle film

Engineering Contradiction:

Improvepellicle film integrityVSAvoidforeign matter adhesion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing foreign matter removal through VUV light irradiation and inert gas flow before the pellicle film is used in semiconductor exposure. This preventive approach eliminates foreign matter in advance, preventing the formation of local hot spots and subsequent film damage during radiation exposure

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses an inert gas atmosphere (nitrogen or rare gas) during VUV light irradiation to prevent oxidation and chemical reactions that could damage the pellicle film. The inert environment protects the film while allowing effective foreign matter removal through photoelectric effects

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If VUV light is used to remove foreign matter, then foreign matter can be effectively removed, but the pellicle film may be damaged by the high energy radiation

Engineering Contradiction:

Improveforeign matter removalVSAvoidpellicle film strength

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies parameter changes by carefully controlling the VUV light irradiation conditions, including irradiation time, light intensity, and wavelength, to achieve effective foreign matter removal while staying below the threshold that would cause pellicle film damage. The inert gas atmosphere also modifies the interaction parameters between VUV light and the film surface

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The inert gas acts as an intermediary medium between the VUV light and the pellicle film. It absorbs excess energy and prevents direct high-energy photon damage to the film while still allowing the photoelectric removal of foreign matter to occur effectively

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If oxygen is present during VUV light irradiation, then the atmosphere is more reactive, but this can cause oxidation and damage to the pellicle film

Engineering Contradiction:

Improvechemical reactivityVSAvoidoxidation damage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the oxygen-containing atmosphere with an inert gas atmosphere (nitrogen or rare gas) during VUV light irradiation. This eliminates oxygen from the environment, preventing oxidation reactions that would damage the pellicle film while maintaining conditions suitable for foreign matter removal through photoelectric effects

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

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 device effectively removes foreign matter from the pellicle film, preventing damage and maintaining the integrity of the film, which in turn helps to suppress decreases in the yield rate of semiconductor production.

Implementation Method 1

a vacuum ultraviolet light generating section generating vacuum ultraviolet light

Methodology Applied

Scientific EffectVacuum ultraviolet light generation: Light

Implementation Method 2

irradiating vacuum ultraviolet light onto a pellicle film in an inert gas atmosphere within the irradiation chamber

Methodology Applied

Scientific EffectVUV light absorption by inert gas: Absorption (EM radiation)

Data Source

PatentEP4560398A1Foreign matter removal device, pellicle production device, pellicle production method, and pellicle

Publication Date: 2025.05.28 MITSUI CHEMICALS INC

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AI summary

The present disclosure provides a foreign matter removing device that includes: a vacuum ultraviolet light generating section generating vacuum ultraviolet light; an irradiation container for irradiating the vacuum ultraviolet light onto a pellicle film; and a gas supplying section supplying inert gas to the irradiation container. The irradiation container has an irradiation chamber at which are provided a gas supply port for supplying the inert gas and a gas discharge port for discharging the inert gas. The gas supplying section is connected to the gas supply port.