Thin Substrate Support for Plasma Processing RF Loss

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Solution Overview

Problem

Conventional substrate support systems in plasma processing experience significant RF power loss on the low frequency side, leading to abnormal discharge issues due to the thickness of the attraction part and potential differences between the substrate and RF electrode, especially when handling difficult-to-etch materials.

Innovation Solution

A substrate support system with a thin substrate attraction part (≤2 mm) and a sandwiched RF electrode part between the attraction and temperature adjuster parts, using materials with low thermal expansion differences and appropriate dielectric properties to minimize RF power loss and abnormal discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick attraction part is used in the substrate support, then the substrate can be held securely, but RF power loss on the low frequency side increases and abnormal discharge occurs

Engineering Contradiction:

Improvesubstrate holding stabilityVSAvoidRF power loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The substrate support is divided into three separate stacked components: substrate attraction part, RF electrode part, and substrate temperature adjuster part. This segmentation allows each part to be optimized independently - the attraction part can be made thin to reduce RF power loss while still providing secure substrate holding through the attraction electrode, and the temperature adjuster part can provide thermal management without interfering with RF performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The RF electrode part serves as an intermediary component between the substrate attraction part and the substrate temperature adjuster part. This intermediate RF electrode part with thickness of 0.5 mm or less acts as a mediator that prevents direct contact between the attraction part and temperature adjuster part, thereby reducing the overall thickness of the attraction path and minimizing RF power loss on the low frequency side.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a thick attraction part is used, then substrate holding is secure, but potential difference between substrate and RF electrode increases causing abnormal discharge

Engineering Contradiction:

Improvesubstrate holding stabilityVSAvoidabnormal discharge

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Dividing the substrate support into separate attraction part, RF electrode part, and temperature adjuster part reduces the thickness of the attraction part, thereby reducing the potential difference between the substrate and RF electrode that causes abnormal discharge.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Changing the thickness parameter of the RF electrode part to 0.5 mm or less optimizes the electrical field distribution and reduces potential differences that lead to abnormal discharge, while maintaining effective substrate holding through the attraction electrode.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If the attraction part and temperature adjuster part are separated, then RF power loss is reduced, but device complexity increases

Engineering Contradiction:

ImproveRF power lossVSAvoidsubstrate support structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

While the attraction part, RF electrode part, and temperature adjuster part are functionally separated to reduce RF power loss, they are merged into a compact stacked configuration where all three parts are vertically aligned and integrated within a small footprint. This merging approach maintains reduced RF power loss while minimizing the overall device complexity and space requirement.

Inventive Principle:

Principle #5Merging (Combining)

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

The solution effectively suppresses RF power loss on the low frequency side and reduces potential differences, preventing abnormal discharge while maintaining high temperature control and uniformity for improved plasma processing.

Implementation Method 1

a substrate attraction part having an attraction electrode for holding the substrate

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

a substrate temperature adjuster having a heater electrode for adjusting a temperature of the substrate

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Implementation Method 3

an RF electrode part to which RF power is supplied

Methodology Applied

Scientific EffectRadio frequency plasma generation: Electromagnetic Induction

Data Source

PatentUS20220415629A1Substrate support, substrate support assembly, and plasma processing apparatus

Publication Date: 2022.12.29 TOKYO ELECTRON LTD

AI summary

A substrate support that supports a substrate, includes a substrate attraction part having an attraction electrode for holding the substrate, an RF electrode part to which RF power is supplied, and a substrate temperature adjuster having a heater electrode for adjusting a temperature of the substrate. The substrate attraction part and the substrate temperature adjuster are stacked with the RF electrode part interposed therebetween.