Substrate Processing Liquid Mixing for Precise Dissolved Gas Control

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Solution Overview

Problem

Existing substrate processing technologies face challenges in accurately adjusting the dissolved oxygen concentration in processing liquids and preventing contamination from particles or metal ions caused by concentration measurement parts.

Innovation Solution

The substrate processing apparatus includes a dual supply liquid system with concentration measurement parts and flow rate adjustment mechanisms to mix the liquids, ensuring accurate dissolved gas concentration and preventing contamination by diverting the supply lines before the measurement parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a concentration measurement part is used to measure dissolved gas concentration in processing liquid, then measurement precision is improved, but particles or metal ions are generated that contaminate the processing liquid

Engineering Contradiction:

Improvedissolved gas concentration measurementVSAvoidparticles and metal ions contamination

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The harmful liquid contacting part is extracted and removed from the concentration measurement part. The patent uses a non-contact measurement method where light passes through the liquid without physical contact, eliminating the source of particles and metal ions while maintaining measurement capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Light is introduced as an intermediary medium to transfer measurement information without physical contact with the processing liquid. The light beam serves as a mediator that carries concentration data without contaminating the liquid, resolving the contradiction between measurement and contamination

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If nitrogen gas is bubbled into processing liquid or ambient atmosphere is decompressed to reduce dissolved oxygen concentration, then dissolved oxygen concentration is reduced, but it is difficult to adjust to an arbitrary set value with high accuracy

Engineering Contradiction:

Improvedissolved oxygen concentrationVSAvoidadjustment accuracy to set value

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

A feedback control system is implemented where the concentration measurement part continuously monitors dissolved gas concentration and feeds this information back to the control unit. The control unit adjusts gas flow rate based on the measured values, enabling precise adjustment to arbitrary set values with high accuracy

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the parameter of gas flow rate dynamically based on real-time concentration measurements. By adjusting the flow rate parameter in response to measured concentration values, the system achieves precise control of dissolved gas concentration to match arbitrary set values

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

This solution allows for precise adjustment of dissolved gas concentrations in processing liquids, reducing contamination risks and enhancing the accuracy and reliability of substrate processing.

Implementation Method 1

a first concentration measurement part provided in the first supply liquid line, for measuring a dissolved concentration of predetermined gas in the first supply liquid

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a second concentration measurement part provided in the second supply liquid line, for measuring a dissolved concentration of the gas in the second supply liquid

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

a mixing part to which the other end of the first branch line and the other end of the second branch line are connected, for mixing the first supply liquid and the second supply liquid, to thereby generate the processing liquid

Methodology Applied

Scientific EffectFluid mixing:

Data Source

PatentUS12211708B2Substrate processing apparatus and substrate processing method

Publication Date: 2025.01.28 SCREEN HOLDINGS CO LTD

AI summary

First and second concentration measurement parts (415, 425) are provided in first and second supply liquid lines (412, 422) in which first and second supply liquids flow, respectively. A dissolved concentration of gas in the second supply liquid is lower than that in the first supply liquid. In the first and second supply liquid lines, respective one ends of first and second branch lines (51, 52) are connected to respective positions on the upstream side of the concentration measurement parts. The other ends of the first and second branch lines are connected to a mixing part (57), and by mixing the first and second supply liquids, a processing liquid is generated. Respective flow rate adjustment parts (58) of the first and second branch lines are controlled on the basis of respective measured values of the first and second concentration measurement parts so that the dissolved concentration of the gas in the processing liquid can become a set value. It is thereby possible to prevent the supply liquid containing particles or the like caused by the concentration measurement part from being contained into the processing liquid to be supplied to a substrate and also to adjust the dissolved concentration of the gas in the processing liquid to the set value with high accuracy.