Flexible Magnet Assembly for Sputtering Film Uniformity

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Solution Overview

Problem

Conventional sputter deposition equipment faces challenges in achieving uniform film deposition due to process phenomena like the 'cross-corner effect' and process drift, leading to variations in deposition rate across the substrate, which cannot be effectively addressed without moving the entire magnet assembly.

Innovation Solution

An adjustable sputter deposition system with a magnet assembly that includes a flexible magnetic control body, allowing for local adjustments to the magnetic field without moving the entire magnet assembly, by bending an elongated flexible magnetic control body to project differently into a gap defined by a magnetic backing plate, thereby compensating for local process conditions and maintaining film uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the entire magnet assembly is moved to adjust process conditions, then film uniformity can be improved, but device complexity and operational difficulty increase

Engineering Contradiction:
Improvefilm uniformityVSAvoidmagnet assembly adjustment complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The magnet assembly is segmented into multiple independent magnet modules arranged in a racetrack configuration. Each module can be independently adjusted to control local magnetic field conditions, allowing precise control of deposition rates across different regions of the substrate without moving the entire assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnet modules are made dynamically adjustable during the deposition process. The ability to move and reposition individual magnet modules enables real-time optimization of magnetic field distribution, allowing the system to adapt to changing process conditions and maintain film uniformity throughout production runs.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the magnet assembly is made locally adjustable, then process conditions can be optimized, but device complexity increases

Engineering Contradiction:
Improvelocal process adjustment capabilityVSAvoidmagnet assembly structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The magnet assembly is divided into discrete, independently controllable magnet modules. This segmentation allows local adjustment of magnetic field strength and distribution at specific positions on the target, providing adaptability to address local process variations without requiring complex adjustments of the entire assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each magnet module can be positioned to create locally optimized magnetic field conditions. This allows different regions of the target to have tailored magnetic field characteristics, enabling local process optimization for specific areas of the substrate while maintaining overall system simplicity through modular design.

Inventive Principle:
Principle #3Local quality

3Device complexity

If conventional magnet assemblies are used, then device simplicity is maintained, but film uniformity deteriorates due to cross-corner effect and process drift

Engineering Contradiction:
Improvemagnet assembly structureVSAvoidfilm uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The magnet modules are designed to be dynamically repositionable during deposition runs. This dynamic capability allows the system to compensate for process drift and maintain optimal magnetic field distribution over time, significantly improving film uniformity compared to static conventional magnet assemblies.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system enables changes in magnetic field parameters (strength, distribution, configuration) by adjusting magnet module positions. This parameter control allows optimization of deposition conditions to eliminate cross-corner effects and maintain consistent film quality across the entire substrate surface.

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

The system achieves exceptional film uniformity by allowing for real-time adjustments to the magnetic field, addressing the 'cross-corner effect' and process drift without the need to move the primary magnets, thus improving the consistency of the deposition process.

Implementation Method 1

The magnet assembly creates a magnetic field comprising field lines that extend from the proximal end of the first magnet, through the sputtering target, along an arc located in front of the sputtering target, back through the sputtering target, to the proximal end of the second permanent magnet, through the second permanent magnet, along a return path, and to the distal end of the first permanent magnet

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

The elongated flexible magnetic body has a length and is differentially bendable along the length so as to project further into the gap at one position along the length than at another position along the length

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

Sputter deposition (or 'sputtering') is one method of depositing such coatings

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP3619735B1Sputtering deposition system with flexible adjustable return path magnet assembly
Publication Date: 2021.07.07 CARDINAL CG CO
  • EP3619735B1 patent drawingFigure 1
  • EP3619735B1 patent drawingFigure 2
  • EP3619735B1 patent drawingFigure 3

AI summary

The invention provides a sputter deposition assembly that includes a sputtering chamber, a sputtering target, and a magnet assembly. The magnet assembly includes a magnetic backing plate comprising an elongated flexible magnetic control body or a plurality of layered metal sheets.