RF Return Path Structure for Process Chamber Arcing Control

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Solution Overview

Problem

Current RF return path designs in process chambers for chemical vapor deposition (CVD) and plasma enhanced CVD (PECVD) are complex and prone to arcing, which can damage the chamber and its components.

Innovation Solution

The proposed apparatus includes a dielectric plate between the chamber body and lid, a substrate support with a central and peripheral region, and a bellows on the flange configured to sealily couple to the dielectric plate, providing an efficient RF return path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current ground path designs are used to direct RF power away from chamber components, then RF power return path is provided, but the design becomes complicated and arcing can still occur in the process chamber

Engineering Contradiction:

ImproveRF power return path effectivenessVSAvoidground path design complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The ground path is segmented into multiple conductive elements: the dielectric plate with conductive layer, the substrate support with conductive flange, and the bellows. Each segment provides a portion of the RF return path, distributing the function across multiple simpler components rather than requiring a single complex structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive layer on the dielectric plate and the conductive flange on the substrate support are electrically connected to establish an equipotential surface. This provides a low-impedance path for RF power return while maintaining uniform potential distribution, reducing the risk of arcing between components.

Inventive Principle:

Principle #12Equipotentiality

2Object-affected harmful factors

If ground path is provided to prevent damage to chamber components, then RF power is directed away from components, but arcing can still occur in the process chamber

Engineering Contradiction:

Improveprotection from RF power damageVSAvoidarcing in process chamber

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The dielectric plate with conductive layer acts as an intermediary between the RF power source and the chamber components. It provides a controlled path for RF power return while the dielectric material prevents direct arcing to the chamber body, and the conductive layer guides the RF current away from sensitive components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces traditional mechanical ground connections with an electromagnetic field-based solution. The conductive layer and flange create a distributed capacitive and conductive coupling that provides RF power return through electromagnetic fields rather than direct mechanical contact, reducing arcing risks.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If RF power is used to activate process gases, then chemical vapor deposition is enabled, but RF power has a tendency to return to source causing potential damage

Engineering Contradiction:

Improvefilm deposition capabilityVSAvoidRF power return control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The conductive path is pre-established through the dielectric plate and substrate support structure before RF power is applied. This preliminary configuration of the RF return path ensures that when RF power is used to activate process gases for film deposition, the power has a predetermined safe path to return to the source without causing damage.

Inventive Principle:

Principle #10Preliminary action

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 design effectively reduces the occurrence of RF leakage, parasitic plasma, and arcing within the process chamber, enhancing the reliability and longevity of the chamber components.

Implementation Method 1

A bellows is disposed on the flange and configured to sealingly couple to the dielectric plate

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

A dielectric plate is disposed between the chamber body and the lid

Methodology Applied

Scientific EffectDielectric: Dielectric

Implementation Method 3

Radio frequency (RF) power may be used to activate the process gases in the process chamber

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 4

Radio frequency (RF) power may be used to activate the process gases in the process chamber

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentUS12340984B2Radio frequency power return path

Publication Date: 2025.06.24 APPLIED MATERIALS INC

AI summary

Embodiments presented herein are directed to radio frequency (RF) grounding in process chambers. In one embodiment, a dielectric plate is disposed between a chamber body and a lid of a process chamber. The dielectric plate extends laterally into a volume defined by the chamber body and the lid. A substrate support is disposed in the volume opposite the lid. The substrate support includes a support body disposed on a stem. The support body includes a central region and a peripheral region. The peripheral region is radially outward of the central region. The central region has a thickness less than a thickness of the peripheral region. A flange is disposed adjacent to a bottom surface of the peripheral region. The flange extends radially outward from an outer edge of the peripheral region. A bellows is disposed on the flange and configured to sealingly couple to the dielectric plate.