EUV Target Supply Device Temperature Control

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Solution Overview

Problem

In extreme ultraviolet light generating apparatuses, the target supply device's temperature control methods lead to uneven melting and oxidation of the target substance, resulting in inefficient discharge and potential oxidation, due to the capacity and heat distribution differences between the tank body and communication portions.

Innovation Solution

The control unit sets the main heater to a temperature higher than the melting point before melting, and the sub-heater to a temperature lower than the melting point until the target substance is melted, then increases the sub-heater temperature above the melting point after melting, ensuring uniform heating and preventing oxidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the main heater and sub-heater are set to the same temperature (higher than melting point) before the target substance is melted, then the target substance can be melted efficiently, but the communication portion experiences thermal expansion and oxidation

Engineering Contradiction:

Improvemelting efficiencyVSAvoidoxidation in communication portion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different temperature settings to different parts of the heating system based on their functional requirements. The main heater is set to a temperature higher than the melting point to efficiently melt the target substance in the tank body portion, while the sub-heater is set to a temperature lower than the melting point to prevent thermal expansion and oxidation in the communication portion. This local differentiation of thermal conditions resolves the contradiction between melting efficiency and prevention of harmful oxidation.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If the sub-heater is set to a temperature lower than the melting point before melting, then oxidation is prevented, but the target substance cannot be discharged efficiently after melting

Engineering Contradiction:

Improveoxidation preventionVSAvoiddischarge efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic temperature control where the sub-heater's temperature setting changes based on the melting state of the target substance. Before melting, the sub-heater operates at a temperature lower than the melting point to prevent oxidation. After melting is complete, the sub-heater temperature is increased above the melting point to enable efficient discharge. This temporal differentiation resolves the contradiction between oxidation prevention and discharge efficiency.

Inventive Principle:

Principle #15Dynamics

3Duration of action of stationary object

If the tank body portion is heated to melt the target substance, then the target substance can be supplied continuously, but the communication portion undergoes thermal expansion causing discharge instability

Engineering Contradiction:

Improvecontinuous supply durationVSAvoiddischarge stability

Core Design Contradiction:

Duration of action of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies differentiated temperature control to different portions of the target supply device. The tank body portion is heated to a temperature sufficient to melt the target substance, enabling continuous supply over extended periods. In contrast, the communication portion is maintained at a lower temperature (below the melting point) before melting to prevent thermal expansion and maintain discharge stability. This spatial differentiation of thermal conditions allows both continuous supply and stable discharge to be achieved simultaneously.

Inventive Principle:

Principle #3Local quality

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

This approach prevents unnecessary oxidation and ensures efficient discharge of the target substance by maintaining the target substance in a melted state within the tank body portion while suppressing thermal expansion and oxidation in the communication portion.

Implementation Method 1

a main heater configured to heat the tank body portion

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

set the main heater to a temperature higher than a melting point of the target substance before the target substance is melted

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

a sub-heater configured to heat the communication portion

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS11360391B2Target supply device, extreme ultraviolet light generating apparatus, and electronic device manufacturing method

Publication Date: 2022.06.14 GIGAPHOTON INC

AI summary

A target supply device includes a tank body portion holding a target substance; a communication portion connected to the tank body portion and including a filter that filters the melted target substance and a nozzle that discharges the target substance having passed through the filter; a main heater that heats the tank body portion; a sub-heater that heats the communication portion; and a control unit, the control unit being configured to set the main heater to a temperature higher than a melting point of the target substance before the target substance is melted, to set the sub-heater to a temperature lower than the melting point of the target substance until the target substance in the tank body portion is melted, and to set the sub-heater to a temperature higher than the melting point of the target substance after the target substance in the tank body portion is melted.