Doped Ceramic Target Sintering for Sputtering Applications

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Solution Overview

Problem

Current methods for producing ceramic targets with high melting points are complex, costly, and require specialized skills, especially for large-area targets, and often involve multiple steps or expensive equipment, limiting their widespread use in applications like sputtering for thin-layer films and electrochemical devices.

Innovation Solution

A process involving mixing a high-melting-point inorganic powder with a dopant powder, followed by sintering at elevated temperatures without extensive compaction, using a crucible resistant to high temperatures, to produce dense ceramics suitable for sputtering targets with improved mechanical and electrical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional sintering techniques (natural sintering or hot pressing) are used to manufacture ceramic targets, then the ceramic density can be improved, but the process complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improveceramic densityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the chemical composition parameters by introducing specific dopants (alumina, silica, magnesia, titania, zirconia, or borax) into the ceramic matrix. This compositional modification enables the ceramic to achieve high density through simple sintering at 900-1100°C without requiring complex hot pressing equipment or multi-step processes, thus resolving the contradiction between density and process complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The dopants act as intermediary substances that facilitate densification during sintering. These additives modify the sintering behavior of the ceramic, enabling particles to pack more efficiently and bond stronger at lower temperatures, achieving high density without the need for complex external pressure application equipment

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If hot pressing technique is used to produce dense ceramics, then the ceramic density is improved, but the equipment cost and operational complexity increase

Engineering Contradiction:
Improveceramic densityVSAvoidmanufacturing ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By modifying the chemical composition with specific dopants, the sintering temperature range is optimized to 900-1100°C, and the sintering mechanism is changed from pressure-dependent to diffusion-dependent. This allows standard kilns to replace expensive hot pressing equipment while achieving comparable or superior density

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses inexpensive dopant materials (alumina, silica, magnesia, titania, zirconia, borax) that can be easily mixed with the ceramic powder. These cheap additives enable the use of simple, readily available sintering equipment rather than requiring investment in expensive hot pressing machinery

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If high pressure compaction is used before sintering, then the green body density is improved, but the process complexity and skill requirement increase

Engineering Contradiction:
Improvegreen body densityVSAvoidoperator skill requirement
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent changes the compaction pressure parameter from high pressure (1 tonne/cm²) to low pressure (less than 5 kg/cm²). The introduction of dopants compensates for the reduced compaction pressure by enhancing particle packing efficiency and sintering shrinkage, achieving high final density without requiring high-pressure equipment or skilled operators

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The dopants are mixed with the ceramic powder in advance to prepare a pre-formulated composite powder. This preliminary action ensures that during low-pressure compaction and subsequent sintering, the dopants are already in optimal positions to facilitate densification, eliminating the need for high-pressure compaction steps

Inventive Principle:
Principle #10Preliminary action

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 method simplifies the production of dense, high-quality ceramic targets with enhanced mechanical and electrical properties, enabling their use in various applications such as sputtering for thin-layer films and electrochemical devices without the need for expensive equipment or specialized skills.

Implementation Method 1

a step of mixing the powder of the basic inorganic material with a second inorganic component, also in powder form, which acts as a dopant for the basic inorganic material

Methodology Applied
Scientific EffectMixing:

Implementation Method 2

a sintering step carried out at an elevated temperature which is preferably greater than 800°C

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

The mixed powder, filled into the crucible, was finally sintered at 1300°C in air for 12 hours

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3360855B1Method for preparing ceramics, ceramics thus obtained and uses thereof, particularly as a target for cathode sputtering
Publication Date: 2020.03.18 HYDRO QUEBEC CORP
  • EP3360855B1 patent drawingFigure 1A~1E
  • EP3360855B1 patent drawingFigure 2A~3
  • EP3360855B1 patent drawingFigure 4~5

AI summary

A process for preparing a ceramic from a basic inorganic material in powder form with a high melting point, comprising a step of mixing the powdered basic inorganic material with a second inorganic component, also in powder form, which acts as a dopant for the basic inorganic material. The dopant consists of a single inorganic material or a mixture of at least two inorganic materials that have a doping effect on the basic inorganic material. The process includes a sintering step carried out at a high temperature. The ceramics obtained, due to their high density, are advantageously used as target elements. The films and electrodes obtained from these ceramics exhibit particularly interesting properties.