Boron Carbide (B4C) Sputtering Targets
Purity: 99.5% Size: 6” Thickness: 0.125”
Sputtering is a well-established thin-film deposition technique capable of coating a wide variety of materials onto substrates of different shapes and sizes. The process using sputter targets is highly repeatable and can be scaled from research and development to medium and large-scale production. Chemical reactions may occur on the target surface, during particle transport, or directly on the substrate depending on the chosen process parameters. Although sputter deposition involves many variables, it provides experts with significant control over film growth and microstructure.
Applications of Sputtering Targets
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Thin Film Deposition:
Sputtering targets are broadly used to deposit thin films by eroding material from a “target” and transferring it onto a “substrate,” such as a silicon wafer. -
Semiconductor Etching:
In semiconductor processing, sputtering targets are used in sputter etching, selected when high etching anisotropy is required and selectivity is not critical. -
Analytical Techniques:
Sputtering is also used for material analysis by controlled removal of surface layers.
A common example is Secondary Ion Mass Spectrometry (SIMS), where the sample is sputtered at a constant rate while the concentration and identity of emitted atoms are captured via mass spectrometry. This allows precise determination of material composition and detection of trace-level impurities. -
Space Applications:
Sputtering naturally occurs in space and is a key mechanism of space weathering, altering the physical and chemical properties of airless bodies such as the Moon and asteroids.
Boron Nitride Overview
Boron nitride (BN) is a heat-resistant, chemically stable refractory compound composed of boron and nitrogen. It appears in multiple crystalline forms that are isoelectronic with carbon-based structures.
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Hexagonal Boron Nitride (h-BN):
Structurally similar to graphite, h-BN is the most stable and softest BN polymorph. It is widely used as a dry lubricant and as an additive in cosmetic formulations due to its low friction and excellent thermal stability. -
Cubic Boron Nitride (c-BN):
Analogous to diamond, c-BN is the second hardest known material. Although slightly softer than diamond, it surpasses diamond in thermal and chemical stability, especially at elevated temperatures and in contact with ferrous materials. Due to these advantages, BN ceramics are commonly used in high-temperature industrial components.
Properties and Advanced Performance
Cubic boron nitride (c-BN) is increasingly utilized as a coating material for cutting tools owing to its exceptional properties:
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High hardness
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Low friction coefficient
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High thermal conductivity
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High electrical resistivity
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Strong wear resistance
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Chemical inertness at high temperatures
BN remains the hardest material after diamond and is more chemically stable than diamond under oxidizing conditions and when machining steel.
Polymorphs in Coating Applications
BN coatings typically use two primary polymorphs:
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h-BN (Hexagonal):
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Soft, lubricating behavior
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Low friction coefficient
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Excellent electrical insulation
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Efficient thermal conductivity
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Commonly used in metal-forming dies and high-temperature forming operations
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c-BN (Cubic):
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Extremely hard
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Ideal for dry cutting, high-speed machining, and processing hard materials
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Widely used in cutting tool coatings
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Sintered c-BN tools exist but have limitations such as high cost, brittle nature, and difficulty forming complex shapes
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Due to the limitations of bulk c-BN tools, demand for thin and thick BN films—for cutting tools, protective coatings, optical layers, and electrical insulation—has increased significantly.
Sputtering for BN Film Deposition
Among various deposition methods, sputtering (a physical vapor deposition, PVD technique) is preferred because it offers:
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Lower coating temperatures
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Ability to deposit extremely thin films
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Excellent coverage of sharp edges and complex geometries
These advantages make sputtering an effective technique for synthesizing BN coatings, particularly in the cubic phase.
