Plasma Processing Stage Electrode Segmentation for Thermal Management

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Solution Overview

Problem

Conventional plasma processing apparatuses face challenges in achieving compatible plasma process performance and electrostatic attraction performance, particularly in preventing thermal damage to substrates and carriers due to radiant heat from heated covers.

Innovation Solution

A plasma processing apparatus with a stage featuring a unipolar electrostatic attraction electrode for the substrate and a bipolar electrostatic attraction electrode for the frame and holding sheet, allowing for improved plasma processing and electrostatic attraction performance by using a cover that can come into contact with the stage for heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cover is used to protect the frame and holding sheet area, then plasma process performance is improved, but thermal damage to the substrate outer peripheral part, holding sheet, and frame occurs due to radiant heat from the heated cover

Engineering Contradiction:

Improveplasma process performanceVSAvoidthermal damage from radiant heat

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A shield member is introduced as an intermediary component between the cover and the substrate/holding sheet/frame. This shield member blocks or redirects the radiant heat from the heated cover, preventing thermal damage to the substrate outer peripheral part, holding sheet, and frame, while allowing the cover to remain in place for plasma process protection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The heat blocking function is extracted from the cover itself and implemented by a separate shield member. This allows the cover to focus on its primary function of protecting the frame and holding sheet area from plasma, while the dedicated shield member handles the thermal protection function.

Inventive Principle:

Principle #2Taking out (Extraction)

2Object-affected harmful factors

If the substrate and carrier are electrostatically attracted to the stage for cooling, then thermal damage from radiant heat is reduced, but plasma process performance and electrostatic attraction performance cannot be made compatible

Engineering Contradiction:

Improvethermal damage reductionVSAvoidplasma process performance compatibility

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The electrostatic attraction system is segmented into two independent systems: a first electrostatic attraction electrode for attracting the substrate to the stage for cooling, and a second electrostatic attraction electrode for attracting the carrier to the stage. This segmentation allows each electrode to be optimized for its specific function without interfering with plasma process performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the stage are assigned different electrostatic attraction characteristics. The first electrostatic attraction electrode creates a localized attraction field for the substrate in the plasma processing area, while the second electrostatic attraction electrode creates a separate attraction field for the carrier in the protected area, allowing each to be optimized for its specific location and function.

Inventive Principle:

Principle #3Local quality

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 configuration enhances both plasma processing and electrostatic attraction performance, effectively reducing thermal damage by ensuring efficient heat transfer from the cover and carrier components to the cooled stage.

Implementation Method 1

the substrate and the carrier are electrostatically attracted to and brought into close contact with the stage (cooled by coolant circulation), and can be cooled by the heat transfer to the stage

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the substrate and the carrier are electrostatically attracted to and brought into close contact with the stage

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 3

a plasma generating section configured to generate plasma in the internal space

Methodology Applied

Scientific EffectPlasma generation: Plasma

Implementation Method 4

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS11355323B2Plasma processing apparatus and method therefor

Publication Date: 2022.06.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A dry etching apparatus plasma processes a wafer held by a carrier having a frame and an holding sheet. The carrier is placed on an electrode unit of a stage provided in a chamber. The electrode unit is cooled by a cooling section configured to cool the electrode unit. An upper face of the electrode unit is at least as large as the back side of the carrier. The holding sheet and the frame are cooled effectively by the heat transfer to the stage.