Boron Carbide (B4C) Sputtering Targets, Indium
Purity: 99.5%, Size: 2”, Thickness: 0.125”
Sputtering is a well-established technology capable of depositing thin films from a wide variety of materials onto substrates of diverse shapes and sizes. The process using sputter targets is repeatable and scalable, suitable for both small research projects and medium- to large-scale production batches. Chemical reactions can occur on the target surface, in-flight, or on the substrate depending on process parameters. Although sputter deposition involves many variables, it provides experts with precise control over film growth and microstructure.
Applications of Sputtering Targets
Sputtering targets are used for film deposition. The deposition process involves eroding material from a “target” source onto a “substrate,” such as a silicon wafer. Semiconductor sputtering targets are used for etching the target, particularly when a high degree of etching anisotropy is required and selectivity is not critical. Sputter targets are also applied in analytical techniques by etching away the target material. One example is secondary ion spectroscopy (SIMS), where the target sample is sputtered at a constant rate. During sputtering, the concentration and identity of atoms are measured using mass spectrometry. Using the sputtering target, the composition of the material can be determined, including detection of extremely low impurity concentrations.
Sputtering targets also have applications in space. Sputtering is a form of space weathering, a process that modifies the physical and chemical properties of airless bodies such as asteroids and the Moon.
Material Overview
Boron carbide is a heat- and chemically-resistant refractory compound of boron and carbon with the chemical formula B4C. It exists in multiple crystalline forms that are isoelectronic with a similarly structured carbon lattice. The hexagonal form is the most stable and softest among B4C polymorphs, making it suitable for use in lubricants and certain industrial additives. The cubic structure variety, analogous to diamond, is called c-B4C; it is softer than diamond but offers superior thermal and chemical stability. Due to these characteristics, boron carbide ceramics are commonly used in high-temperature and wear-resistant applications.
Properties and Advantages
Cubic boron carbide (c-B4C) is increasingly employed as a coating material for cutting tools due to its outstanding mechanical and chemical properties. Key properties of boron carbide include:
-
High hardness
-
Low friction coefficient
-
Good thermal conductivity
-
High electrical resistivity
-
High wear resistance
-
Chemical inertness at elevated temperatures
Boron carbide is among the hardest materials available after diamond and surpasses diamond in chemical stability against oxygen and ferrous materials at high temperatures.
Polymorphs and Coating Applications
Boron carbide coatings primarily consist of two polymorphs: hexagonal boron carbide (h-B4C) and cubic boron carbide (c-B4C). Hexagonal boron carbide is soft, has a low friction coefficient, and is electrically insulating and thermally conductive. It is widely applied as a solid lubricant in metal forming dies and high-temperature metal forming processes.
In contrast, cubic boron carbide exhibits extreme hardness and other superior properties, making it an ideal coating material for cutting tools. Its use has increased in applications such as dry cutting, high-speed machining, and cutting hard materials. Sintered c-B4C cutting tools are widely used, though they are limited by high cost, poor ductility, and difficulty forming complex tool shapes.
The demand for B4C thin and thick films has expanded not only for cutting applications but also for protective coatings, optical coatings, and electrical insulating layers. Among various coating methods, sputtering—a physical vapor deposition (PVD) process—has gained prominence due to lower coating temperatures, the ability to deposit thinner films, and the capability to coat sharp edges and complex forms.
