Electrostatic Chuck Charge Measurement for Reliable Dechucking

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Solution Overview

Problem

In substrate processing apparatuses, residual charges on electrostatic chucks can cause substrate damage and positioning issues during dechucking, and frequent charge neutralization reduces throughput.

Innovation Solution

A substrate processing apparatus with a charge amount measurement unit, a charge neutralization mechanism, and a retreating mechanism that measures and neutralizes charges on the substrate attraction surface without hindering the treatment process, using a shield member with a sector-shaped opening to accurately detect charge distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If charge neutralization is performed frequently to prevent substrate damage and positioning issues, then substrate processing reliability is improved, but throughput deteriorates due to repeated interruptions

Engineering Contradiction:

Improvesubstrate processing reliabilityVSAvoidthroughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The charge amount measurement unit measures the charge amount on the mounting table surface in advance before substrate processing. The controller determines whether charge neutralization is needed based on the measured charge amount, allowing neutralization to be performed only when necessary rather than frequently, thus preventing substrate damage while maintaining throughput

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the charge amount on the mounting table surface using the measurement unit and adjusts the charge neutralization operation based on the measured values. The controller compares the measured charge amount against thresholds and activates the neutralization mechanism only when the charge amount exceeds acceptable levels, creating a closed-loop control system that optimizes both reliability and productivity

Inventive Principle:

Principle #23Feedback

2Measurement precision

If a charge amount measurement unit is positioned facing the substrate attraction surface to accurately measure charge distribution, then measurement precision is improved, but the measurement unit interferes with substrate treatment process

Engineering Contradiction:

Improvecharge distribution measurement precisionVSAvoidsubstrate treatment throughput

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The measurement unit is configured to move between a measurement position where it faces the substrate attraction surface to accurately measure charge distribution, and a retreated position where it moves away to avoid interfering with substrate treatment. The retreating mechanism enables the measurement unit to dynamically change its position based on whether measurement or processing is the active operation, thus achieving both precise measurement and uninterrupted substrate treatment

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The retreating mechanism acts as an intermediary that coordinates the measurement unit's position. When substrate treatment is ongoing, the retreating mechanism moves the measurement unit away from the processing area. When measurement is required, it positions the measurement unit facing the attraction surface. This intermediary mechanism resolves the conflict between measurement precision and treatment throughput

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Prevents substrate damage and positioning errors by accurately measuring and neutralizing charges on the electrostatic chuck, maintaining throughput by performing charge neutralization only when necessary.

Implementation Method 1

a mounting table disposed in the processing chamber and configured to attract and hold the substrate using an electrostatic attractive force

Methodology Applied

Scientific EffectElectrostatic attractive force: Electrostatics

Implementation Method 2

a charge amount measurement unit disposed in the processing chamber and configured to measure charge amount of a substrate attraction surface of the mounting table

Methodology Applied

Scientific EffectCharge amount measurement:

Implementation Method 3

a charge neutralization mechanism configured to neutralize the substrate attraction surface of the mounting table

Methodology Applied

Scientific EffectCharge neutralization:

Data Source

PatentUS11862439B2Substrate processing apparatus and charge neutralization method for mounting table

Publication Date: 2024.01.02 TOKYO ELECTRON LTD

AI summary

In a substrate processing apparatus for processing a substrate, a processing chamber accommodating the substrate is provided. A mounting table is disposed in the processing chamber and configured to attract and hold the substrate using an electrostatic attractive force. A charge amount measurement unit is disposed in the processing chamber and configured to measure charge amount of a substrate attraction surface of the mounting table. A charge neutralization mechanism is configured to neutralize the substrate attraction surface of the mounting table. A retreating mechanism is configured to make the charge amount measurement unit retreat from a measurement position facing the substrate attraction surface of the mounting table.