Movable RF Source for Spatial ALD Uniformity

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Solution Overview

Problem

Spatial atomic layer deposition (ALD) systems face limitations such as leading edge thickness variations, trailing edge contamination, and non-uniform feature surface coverage due to static plasma sources, which can cause device damage and asymmetrical film profiles.

Innovation Solution

A spatial ALD system with a movable RF source integrated into a shuttle that supports the substrate, allowing RF power to be synchronized with the substrate's movement through different zones, ensuring plasma generation only where needed, thus minimizing damage and achieving uniform deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a static plasma source is used in spatial ALD, then the plasma can be maintained continuously, but leading edge thickness variations and trailing edge contamination occur

Engineering Contradiction:

Improvecontinuous plasma maintenanceVSAvoidfilm thickness uniformity

Core Design Contradiction:

Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The patent makes the plasma source movable rather than stationary, allowing it to move synchronously with the substrate during deposition. This dynamic configuration ensures that the plasma front remains positioned relative to the substrate, preventing leading edge thickness variations and trailing edge contamination while maintaining continuous plasma for efficient deposition.

Inventive Principle:

Principle #15Dynamics

2Productivity

If a moving plasma front is used in spatial ALD, then deposition efficiency is improved, but device damage occurs due to induced currents

Engineering Contradiction:

Improvedeposition efficiencyVSAvoiddevice damage from induced currents

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a conductive substrate holder as an intermediary between the moving plasma source and the substrate. The holder provides a low-impedance path for induced currents, preventing charge accumulation and device damage while allowing the plasma to move efficiently for high deposition rates.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the substrate is moved through a static plasma field, then spatial ALD can be implemented, but asymmetric film profiles and non-uniform feature deposition occur

Engineering Contradiction:

Improvespatial ALD capabilityVSAvoidfeature deposition uniformity

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent synchronizes the movement of the plasma source with the substrate movement, maintaining a consistent spatial relationship between the plasma front and substrate features. This dynamic coordination ensures uniform plasma exposure across all substrate features, eliminating asymmetric profiles and achieving consistent deposition throughout the feature array.

Inventive Principle:

Principle #15Dynamics

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 enables efficient and uniform thin film deposition across the substrate, reducing edge thickness variations and feature surface coverage issues, while maintaining the benefits of temporal ALD systems by synchronizing plasma strike events with substrate movement.

Implementation Method 1

spatial atomic layer deposition (ALD) system... RF power source... RF power electrode and an RF ground electrode... plasma generation

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

RF power source... RF power electrode and an RF ground electrode coupled to an RF power source

Methodology Applied

Scientific EffectRadio frequency heating: Dielectric Heating

Implementation Method 3

a first zone for delivery of first reactant gases to be absorbed by a surface of a substrate

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 4

a third zone for delivery of second reactant gases to be reacted with the first reactant gases that were absorbed by the surface of the substrate

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS10550469B2Plasma excitation for spatial atomic layer deposition (ALD) reactors

Publication Date: 2020.02.04 LAM RES CORP

AI summary

A spatial atomic layer deposition (ALD) system is disclosed. The system includes a chamber that includes a plurality of zones oriented along a track. Also included is a shuttle that is configured to support the substrate and transport the substrate to each of the plurality of zones to enable deposition of a thin film. The shuttle includes an RF power electrode and an RF ground electrode coupled to an RF power source. The RF electrode and the RF ground electrode are each embedded in the shuttle, such that power provided by the RF power source to the shuttle moves with the shuttle to each of the zones. The RF power source is configured to be activated in synchronization with moving the shuttle to one of the zones.