RF Sputter Deposition Source Defined Return Path

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Solution Overview

Problem

RF sputtering processes often experience arcing and parasitic plasma due to undefined RF return paths in vacuum deposition systems, leading to unstable deposition conditions and target damage.

Innovation Solution

A defined RF return path is established using a conductor rod extending through the vacuum chamber wall, connected to a shielding box and RF power supply, providing a controlled path for RF currents and reducing arcing and parasitic plasmas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional RF sputtering system is used without a defined RF return path, then the system structure is simpler, but arcing and parasitic plasma occur leading to unstable deposition conditions and target damage

Engineering Contradiction:
Improvedeposition stabilityVSAvoidRF return path structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A conductor rod is introduced as an intermediary component to establish a defined RF return path between the RF power supply and the vacuum chamber wall. This mediator provides a controlled pathway for RF currents, preventing uncontrolled arcing and parasitic plasma formation while maintaining system reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The RF return path is segmented into distinct components: the conductor rod extending through the vacuum chamber wall, the RF power supply connection, and the target connection. This segmentation allows each component to be optimized independently and simplifies the overall system design while ensuring stable RF current flow.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If shielding box is positioned close to the wall portion, then the structure is more compact, but RF current paths become undefined causing arcing

Engineering Contradiction:
Improvearcing reductionVSAvoidshielding box volume
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The distance parameter between the shielding box and the vacuum chamber wall is optimized to maintain a defined RF current path. By controlling this spatial parameter, the system prevents arcing and parasitic plasma formation while minimizing the volume occupied by the shielding box, achieving a balance between harmful factor reduction and compactness.

Inventive Principle:
Principle #35Parameter changes

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 solution enhances the stability of deposition conditions, improves layer quality, and reduces or eliminates arcing and target damage, ensuring consistent and efficient sputter deposition.

Implementation Method 1

an RF power supply for providing RF power to the target

Methodology Applied
Scientific EffectRadio frequency energy: Electromagnetic Induction

Implementation Method 2

a conductor rod extending through the wall portion from inside of the vacuum chamber to outside of the vacuum chamber, wherein the conductor rod is connected to one or more components inside of the vacuum chamber and wherein the conductor rod is connected to the RF power supply outside of the vacuum chamber to generate a defined RF return path

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

the one or more components comprises a shielding box, the shielding box is connected to the conductor rod

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 4

Sputtering generates a stream of coating material by sputtering a target through the use of a plasma. During this a process in which material is released from the surface of the target by collision with high-energy particles from the plasma

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP3066679B1Radio frequency (RF) - sputter deposition source, deposition apparatus and method of assembling thereof
Publication Date: 2020.04.15 APPLIED MATERIALS INC
  • EP3066679B1 patent drawingFigure 1~2
  • EP3066679B1 patent drawingFigure 3A
  • EP3066679B1 patent drawingFigure 3B

AI summary

A sputter deposition source for sputter deposition in a vacuum chamber is described. The source includes a wall portion of the vacuum chamber; a target providing a material to be deposited during the sputter deposition; an RF power supply for providing RF power to the target; a power connector for connecting the target with the RF power supply; and a conductor rod extending through the wall portion from inside of the vacuum chamber to outside of the vacuum chamber, wherein the conductor rod is connected to one or more components inside of the vacuum chamber and wherein the conductor rod is connected to the RF power supply outside of the vacuum chamber to generate a defined RF return path through the conductor rod.