Process Container Cleaning for Residual Fluorine Removal

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Solution Overview

Problem

The productivity of semiconductor device manufacturing is deteriorated due to residual fluorine in the process container after cleaning, which affects subsequent substrate processing, leading to reduced deposition rates and film quality.

Innovation Solution

A three-step cleaning process is employed, involving the use of a fluorine-based gas at a first temperature, followed by physical desorption with a non-reactive inert gas at a higher temperature, and chemical desorption with a reactive gas, to effectively remove residual fluorine from the process container.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a fluorine-based gas is supplied into the process container to clean the inside after substrate processing, then substances adhered to the process container are removed, but residual fluorine remains in the process container causing productivity deterioration in subsequent substrate processing

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidsubstrate processing productivity

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The cleaning process is divided into multiple sequential steps: first supplying a fluorine-based gas to remove adhered substances, then supplying a non-reactive gas to physically desorb residual fluorine, and finally supplying a reactive gas to chemically desorb residual fluorine. This segmentation of the cleaning process allows thorough removal of contaminants while eliminating residual fluorine that would harm subsequent processing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A non-reactive gas (intermediary substance) is introduced between the fluorine-based gas cleaning step and the subsequent substrate processing. This intermediary gas physically desorbs residual fluorine through temperature difference and flow, preventing the residual fluorine from affecting the next substrate processing while not reacting with the fluorine itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the process container is thoroughly cleaned to remove all residual fluorine, then substrate processing productivity is maintained, but the cleaning process time and complexity increase

Engineering Contradiction:

Improvesubstrate processing productivityVSAvoidcleaning process time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The cleaning process is divided into three distinct steps with specific purposes: (1) fluorine-based gas supply for removing adhered substances, (2) non-reactive gas supply for physical desorption of residual fluorine, and (3) reactive gas supply for chemical desorption of residual fluorine. This segmentation allows each step to be optimized for its specific function, achieving thorough cleaning without excessive time consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cleaning process utilizes parameter changes including temperature differences between steps and flow rate variations of different gases. The non-reactive gas is supplied at a higher temperature than the fluorine-based gas step to enhance physical desorption, while flow rates are adjusted to optimize both cleaning effectiveness and process time.

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 approach allows for efficient removal of residual fluorine, preventing productivity deterioration and ensuring stable substrate processing without extending downtime, thereby maintaining high deposition rates and film quality.

Implementation Method 1

supplying a first gas including a fluorine-based gas at a first flow rate into the process container and exhausting the inside of the process container to remove substances adhered

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

physically desorbing and removing residual fluorine in the process container set at a second temperature higher than the first temperature by supplying a second gas, which does not react chemically with fluorine under the second temperature

Methodology Applied

Scientific EffectPhysical desorption: Desorption

Implementation Method 3

chemically desorbing and removing residual fluorine in the process container set at a third temperature higher than the first temperature by supplying a third gas, which reacts chemically with fluorine under the third temperature

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS12195848B2Method of cleaning, method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

Publication Date: 2025.01.14 KOKUSAI DENKI KK

AI summary

There is provided a technique of cleaning an inside of a process container, including: (a) removing substances adhered in a process container set at a first temperature by supplying a first gas at a first flow rate into the process container and exhausting the inside of the process container; (b) physically desorbing and removing residual fluorine in the process container set at a second temperature by supplying a second gas at a second flow rate into the process container and exhausting the inside of the process container; and (c) chemically desorbing and removing residual fluorine in the process container set at a third temperature by supplying a third gas at a third flow rate into the process container and exhausting the inside of the process container.