Plasma Processing Reactor Segmented Electrode Cleaning

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Solution Overview

Problem

Current capacitively coupled plasma systems used for chamber cleaning in semiconductor manufacturing degrade electrostatic chucks and are inefficient in cleaning peripheral hardware, leading to reduced manufacturing throughput and yield.

Innovation Solution

The implementation of a plasma processing chamber with both capacitive and inductive plasma sources, where the inductive plasma is used to create a high-density plasma specifically for cleaning the peripheral regions, reducing ion energy impact on electrostatic chucks and enhancing cleaning efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitively coupled plasma is used for chamber cleaning, then cleaning effectiveness is improved, but electrostatic chuck lifetime is reduced due to ion bombardment

Engineering Contradiction:
Improvechamber cleaning effectivenessVSAvoidelectrostatic chuck lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The bottom electrode assembly is segmented into an inner bottom electrode (electrostatic chuck) and an outer bottom electrode. During cleaning, plasma is generated between the top electrode and the outer bottom electrode, spatially separating the cleaning zone from the electrostatic chuck region, thus protecting the chuck from ion bombardment while maintaining cleaning effectiveness

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The outer bottom electrode acts as an intermediary that absorbs the ion bombardment and plasma cleaning action, protecting the inner bottom electrode (electrostatic chuck) from direct exposure to high-energy ions while still enabling effective chamber cleaning

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If capacitively coupled plasma is concentrated in the center region, then substrate processing is improved, but peripheral chamber hardware cleaning is insufficient

Engineering Contradiction:
Improvesubstrate processing qualityVSAvoidperipheral hardware cleanliness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The plasma generation is configured with different characteristics in different regions: the inner region maintains capacitively coupled plasma for substrate processing, while the outer region generates plasma between the top electrode and outer bottom electrode for peripheral cleaning, giving each region the plasma quality it needs

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The plasma cleaning action is extended to a new spatial dimension by utilizing the outer bottom electrode region, which is radially outward from the substrate area. This creates an additional plasma generation zone that targets peripheral hardware without interfering with substrate processing

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 approach extends the lifetime of electrostatic chucks, improves manufacturing throughput, and ensures effective cleaning of peripheral chamber hardware, maintaining chamber reproducibility and increasing substrate yield.

Implementation Method 1

The top capacitive electrode and the inner bottom electrode are configured to convert a process gas into a capacitively coupled plasma within a first region of a cavity defined between the bottom electrode assembly and the top electrode assembly

Methodology Applied
Scientific EffectCapacitively coupled plasma: Plasma

Implementation Method 2

The top capacitive electrode and the outer bottom electrode are configured to convert a process gas into a capacitively coupled plasma within a second region of the cavity

Methodology Applied
Scientific EffectCapacitively coupled plasma: Plasma

Implementation Method 3

The electrostatic chuck is used to support the substrate during substrate etching

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP1993745B1Plasma processing reactor
Publication Date: 2012.04.11 LAM RES CORP
  • EP1993745B1 patent drawingFigure 1A
  • EP1993745B1 patent drawingFigure 1B~1C
  • EP1993745B1 patent drawingFigure 2

AI summary

Broadly speaking, the embodiments of the present invention provide an improved chamber cleaning mechanism, apparatus and method. The present invention can also be used to provide additional knobs to tune the etch processes. In one embodiment, a plasma processing chamber configured to generate a plasma includes a bottom electrode assembly with an inner bottom electrode and an outer bottom electrode disposed outside of the inner bottom electrode, wherein the inner bottom electrode is configured to receive a substrate. The plasma processing chamber also includes a top electrode assembly with a top electrode, wherein the top capacitive electrode is disposed directly above the inner and outer bottom electrodes.