Electrostatic Chuck Voltage Control for Microparticle Adherence

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Solution Overview

Problem

In semiconductor manufacturing, microparticles generated during plasma processing can adhere to substrates, affecting uniform processing and device performance, and existing methods do not adequately address the reduction of these particles before substrate transfer.

Innovation Solution

Applying voltage to an electrostatic chuck to reduce the potential difference between the focus ring and the substrate, which surrounds the chuck, to minimize the adherence of microparticles to the substrate by moving them from the focus ring to the substrate, and incorporating a cleaning process before substrate transfer to further reduce adherence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cleaning is performed prior to substrate transfer, then microparticles are removed from the processing container, but microparticles may be adhering to the substrate during transfer

Engineering Contradiction:
Improvesubstrate cleanlinessVSAvoidmicroparticle adherence
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies voltage to the electrostatic chuck before the substrate is transferred into the processing container. This preliminary action creates an electrostatic field that prevents microparticles from adhering to the substrate during transfer, addressing the problem that occurs after cleaning when substrates are vulnerable to particle contamination

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical cleaning methods with an electrostatic field-based approach. By applying voltage to the electrostatic chuck, the system uses electrostatic forces to control microparticle behavior, preventing adherence without requiring mechanical contact or complex cleaning mechanisms

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If voltage is applied to electrostatic chuck to reduce potential difference, then microparticle adherence is reduced, but additional control steps are required

Engineering Contradiction:
Improvemicroparticle adherenceVSAvoidvoltage control system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The electrostatic chuck serves multiple functions: it holds the substrate during processing and also controls microparticle adherence by applying voltage. This multi-functionality reduces the need for separate control systems, as the same component performs both substrate positioning and particle management

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the electrical parameter (voltage) of the electrostatic chuck to control microparticle behavior. By adjusting the voltage level, the system can reduce the potential difference between the chuck and substrate, thereby controlling electrostatic forces that cause microparticle adherence

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

Effectively reduces the adherence of microparticles to the substrate, ensuring more consistent and reliable plasma processing by suppressing the movement of microparticles from the focus ring to the substrate, thereby enhancing processing quality.

Implementation Method 1

applying voltage to an electrostatic chuck configured to electrostatically attract the substrate to be processed in a processing container

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP2843690B1Method for control of adherence of microparticles to base material to be processed, and processing device
Publication Date: 2020.01.22 TOKYO ELECTRON LTD
  • EP2843690B1 patent drawingFigure 1
  • EP2843690B1 patent drawingFigure 2
  • EP2843690B1 patent drawingFigure 3

AI summary

The present invention includes the following steps: a step in which prior to loading a base material to be processed into a processing vessel, voltage is applied in the processing vessel to an electrostatic chuck that electrostatically adsorbs to the base material to be processed; and a step in which after voltage has been applied to the electrostatic chuck, the base material to be processed is conveyed into the processing vessel. In the step for applying voltage to the electrostatic chuck, voltage is applied to the electrostatic chuck so as to reduce the difference in potential between a focus ring disposed so as to surround the electrostatic chuck and the base material to be processed.