Adjustable Gap RF Plasma Reactor with Cantilever Assembly

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Solution Overview

Problem

Next-generation device fabrication requires improved plasma processing equipment to maintain uniformity across larger substrates and smaller features, especially during multistep recipes like Dual Damascene Etch, where existing technologies face challenges in maintaining uniformity and adjusting gaps between electrodes effectively.

Innovation Solution

An adjustable gap capacitively coupled RF plasma reactor with a cantilever assembly, bellows arrangement for vacuum sealing, and a non-contact particle seal, allowing for vertical movement of the lower electrode and upper electrode to maintain a uniform RF field and prevent particle migration, facilitating uniform etching across large substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the gap between electrodes is adjusted to maintain uniform etching across large substrates, then etching uniformity is improved, but device complexity increases due to the need for adjustable electrode positions and vacuum sealing mechanisms

Engineering Contradiction:

Improveetching uniformityVSAvoidelectrode adjustment mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The lower electrode is made movable rather than fixed, allowing dynamic adjustment of the gap between electrodes. The cantilever assembly with actuation mechanism enables vertical movement of the lower electrode to change the gap distance, while bellows provide flexible vacuum sealing that accommodates this movement. This dynamic configuration allows optimization of etching uniformity across different substrate sizes and process conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Bellows are introduced as an intermediary component between the movable lower electrode and the fixed chamber wall. The bellows provide flexible vacuum sealing that mediates between the need for electrode movement and the requirement for vacuum integrity. This intermediary element enables smooth vertical movement of the electrode assembly while maintaining the vacuum environment necessary for plasma processing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a seal is provided at the opening in the chamber sidewall to maintain vacuum, then vacuum integrity is improved, but particle contamination increases due to contact seals

Engineering Contradiction:

Improvevacuum integrityVSAvoidparticle contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The traditional mechanical contact seal is replaced with a magnetic field-based non-contact seal. A magnetic field is generated across the opening in the chamber sidewall to prevent particle migration while allowing the cantilever assembly to move vertically. This substitution eliminates mechanical contact that could generate particles, while maintaining vacuum integrity through magnetic field confinement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the lower electrode is made movable for gap adjustment, then process adaptability is improved, but manufacturing precision may worsen due to potential positioning errors

Engineering Contradiction:

Improvegap adjustment capabilityVSAvoidelectrode positioning accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Position sensors are implemented to provide feedback on the vertical position of the lower electrode. This feedback mechanism enables precise control and monitoring of the gap distance between electrodes. The actuation mechanism can be controlled to achieve accurate positioning, and the feedback system allows for correction of any positioning errors, maintaining manufacturing precision while enabling adaptable gap adjustment.

Inventive Principle:

Principle #23Feedback

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

Enables precise adjustment of the gap between electrodes to maintain uniform etching across large substrates, improving device yields by ensuring consistent plasma processing and preventing particle contamination within the vacuum chamber.

Implementation Method 1

bellows arrangement providing a vacuum seal between the arm unit and the sidewall

Methodology Applied

Scientific EffectVacuum seal: Vacuum

Implementation Method 2

non-contact particle seal

Methodology Applied

Scientific EffectNon-contact particle seal:

Implementation Method 3

capacitively coupled RF plasma reactor

Methodology Applied

Scientific EffectRF plasma generation: Electromagnetic Induction

Data Source

PatentUS8735765B2Adjustable gap capacitively coupled RF plasma reactor including lateral bellows and non-contact particle seal

Publication Date: 2014.05.27 LAM RES CORP

AI summary

A plasma processing chamber includes a cantilever assembly and at least one vacuum isolation member configured to neutralize atmospheric load. The chamber includes a wall surrounding an interior region and having an opening formed therein. A cantilever assembly includes a substrate support for supporting a substrate within the chamber. The cantilever assembly extends through the opening such that a portion is located outside the chamber. The chamber includes an actuation mechanism operative to move the cantilever assembly relative to the wall.