Titanium Boride Sputtering Targets
Titanium boride, which has the chemical formula of TiB2, is a well-known ceramic compound with hexagonal structure. The high hardness and Young's modulus of titanium boride as well as its chemical resistance are attributed to crystal structure and atomic bonding of the compound.
Due to these properties, titanium boride films have been considered as protective coatings for several applications, including wear and corrosion protection of magnetic recording media and cutting tools. Titanium boride thin films were obtained by various techniques, such as reactive sputtering, plasma enhanced CVD, ion beam sputtering, pulsed laser deposition and rf- and dc-magnetron sputtering. Among these techniques, dc-magnetron sputtering appears to be the most appropriate method for protective coatings applications due to the low deposition temperature, the possibility of using substrates with complicated geometries and the relatively high deposition rate without the use of poison gases.
The titanium boride films deposited using this technique have attracted increasing attention due to their mechanical and tribological properties. Despite intensive investigation, only a few commercial applications of titanium boride films exist. The main reason is the observed high compressive stress of the films. It has been recognized that the stress in coatings, built-up either during or after their deposition, may significantly affect their performance. Films can fail by buckling or cracking depending on the state of stress. Low-stress super-hard titanium boride films were obtained by controlling both the substrate temperature and ion bombardment.