Boron Carbide (B4C) Sputtering Targets
Purity: 99.5%, Size: 8”, Thickness: 0.125”
Sputtering is a proven technology used to deposit thin films from a wide range of materials onto substrates of various shapes and sizes. The process using sputter targets is consistent and can be scaled from small research and development projects to production batches involving medium to large substrate areas. Chemical reactions may occur on the target surface, during transport, or on the substrate depending on process parameters. Although sputter deposition involves many variables, it provides experts with extensive control over film growth and microstructure.
Applications of Sputtering Targets;
Sputtering targets are used for film deposition. This deposition method involves eroding material from a “target” source onto a “substrate,” such as a silicon wafer.
Semiconductor sputtering targets are used for etching when a high degree of etching anisotropy is required and selectivity is not a concern.
Sputter targets are also used in analytical processes by etching away the target material.
One example occurs in secondary ion spectroscopy (SIMS), where the target sample is sputtered at a constant rate. As sputtering takes place, the concentration and identity of ejected atoms are measured through mass spectrometry. With the help of the sputtering target, the composition of the material can be determined, and even extremely low concentrations of impurities can be detected.
Sputtering targets also have applications in space. Sputtering is one form of space weathering, a process that alters the physical and chemical properties of airless bodies such as asteroids and the Moon.
Boron Nitride Overview
Boron nitride is a heat-resistant and chemically stable refractory compound composed of boron and nitrogen, with the chemical formula BN. It exists in several crystalline forms that are isoelectronic with similarly structured carbon lattices. The hexagonal form, analogous to graphite, is the most stable and softest BN polymorph and is widely used as a lubricant and as an additive in cosmetic products. The cubic structure, similar to diamond, is known as c-BN; although softer than diamond, it offers superior thermal and chemical stability. Because of these properties, boron nitride ceramics are traditionally used in high-temperature equipment.
Properties and Performance
Cubic boron nitride (c-BN) has become an important coating material for cutting tools due to its excellent mechanical and chemical characteristics. Key properties of boron nitride include high hardness, low friction coefficient, good thermal conductivity, high electrical resistivity, strong wear resistance, and chemical inertness at elevated temperatures. Boron nitride is the hardest material after diamond and surpasses diamond in chemical stability against oxygen and ferrous materials at high temperatures.
Polymorphs and Coating Applications
Boron nitride coatings primarily use two polymorphs: hexagonal boron nitride (h-BN) and cubic boron nitride (c-BN). Hexagonal boron nitride is known for being soft, having a low friction coefficient, and functioning as a lubricant at both low and high temperatures. It is electrically insulating, thermally conductive, and widely applied as a solid lubricant in metal-forming dies and high-temperature forming processes.
In contrast, cubic boron nitride exhibits high hardness and other exceptional properties, making it a suitable coating material for cutting tools. Its use has increased in applications such as dry cutting, high-speed machining, and processing hard materials. Sintered c-BN cutting tools are widely available, though they face limitations such as high cost, poor ductility, and challenges in forming various tool shapes.
