Substrate Liquid Processing Apparatus Concentration Control

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Solution Overview

Problem

Conventional substrate liquid processing apparatuses face inefficiencies due to increased impurity concentrations and reduced etching capability over repeated processing, requiring frequent liquid exchanges that decrease throughput and may not maintain optimal silicon concentrations in etching liquids.

Innovation Solution

An apparatus with a processing liquid storage unit, an aqueous solution supply unit, and a processing liquid discharging unit, controlled by a unit that supplies a solution of different concentration and temperature to maintain chemical agent balance, allowing for quick liquid updates without altering the processing liquid concentration, using a heating unit and water supply to adjust the liquid's concentration and level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the processing liquid is periodically exchanged to maintain chemical agent concentration, then the processing capability is preserved, but the throughput decreases due to liquid exchange time

Engineering Contradiction:

Improveprocessing capabilityVSAvoidthroughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary actions by continuously monitoring the chemical agent concentration and automatically replenishing the processing liquid before the concentration drops below the effective range, eliminating the need for periodic complete liquid exchanges and maintaining continuous substrate processing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system employs feedback control by detecting the chemical agent concentration in the processing liquid and automatically adjusting the replenishment amount based on the detected concentration, ensuring the concentration is maintained within the effective range while minimizing liquid exchange operations

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If all processing liquid is wasted and fully replenished to maintain concentration, then the processing quality is maintained, but the time and cost increase

Engineering Contradiction:

Improveprocessing qualityVSAvoidliquid exchange time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

Instead of completely replacing the processing liquid, the system performs partial replenishment by adding only the necessary amount of fresh processing liquid to maintain the chemical agent concentration within the effective range, reducing both time loss and liquid waste

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system monitors and maintains the chemical agent concentration parameter within an effective range rather than requiring complete replacement, allowing the processing liquid to be partially replenished based on concentration measurements, thus reducing exchange time and cost

Inventive Principle:

Principle #35Parameter changes

3Reliability

If dummy substrates are immersed to adjust silicon concentration after full liquid exchange, then the concentration is corrected, but the processing time increases

Engineering Contradiction:

Improveconcentration accuracyVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system uses the processing liquid itself to self-regulate its concentration through controlled replenishment based on detected concentration levels, eliminating the need for dummy substrates to adjust silicon concentration and reducing additional processing time

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system implements feedback control by detecting the silicon concentration and automatically controlling the replenishment of fresh processing liquid to maintain the concentration within the effective range, replacing the dummy substrate method with a more efficient automated control system

Inventive Principle:

Principle #23Feedback

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

Enables efficient and satisfactory substrate processing by maintaining the chemical agent concentration and liquid level, reducing the time required for liquid exchanges and preserving the apparatus's throughput.

Implementation Method 1

a heating unit configured to heat the aqueous solution after the aqueous solution is supplied to the processing liquid storage unit

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS10985035B2Substrate liquid processing apparatus, substrate liquid processing method and computer readable recording medium having substrate liquid processing program recorded therein

Publication Date: 2021.04.20 TOKYO ELECTRON LTD

AI summary

Disclosed is a method for performing a liquid processing on a substrate using an aqueous solution of a chemical agent at a predetermined concentration as a processing liquid. The method includes: storing the processing liquid in a processing liquid storage unit; and supplying an aqueous solution of the chemical agent at a different concentration from the concentration of the processing liquid to the processing liquid storage unit, discharging the processing liquid from the processing liquid storage unit so as to update the processing liquid stored in the processing liquid storage unit. The aqueous solution in a predetermined amount is supplied to the processing liquid storage unit, and the processing liquid is discharged from the processing liquid storage unit, the processing liquid containing the chemical agent in the same amount as the amount of the chemical agent contained in the aqueous solution supplied to the processing liquid storage unit.