Effect of the substrate material on diamond CVD coating properties

Interface study of diamond films grown on (100) silicon

“…In order for diamond to reach its true potential, high quality film must be grown on economically viable, non-diamond substrate [4]. For instance, the heteroepitaxy of diamond films on Si substrate via chemical vapor deposition (CVD) has a potential for a variety of applications, such as SAW filters, heat sinks, and field emission displays [5 -7].…”

Diamond deposition on thin cylindrical substrates

“…[2][3][4] The samples obtained after abrading with a mixture of powders (Mo, W and diamond) are presented in Figs. Rapid formation of the carbide layer and the extremely high diamond nucleation density on molybdenum, 11 as well as our positive experience, 10 were the reasons for choosing Mo as a component in the seeding mixture. 1c, and a detail of the fiber nodular end in Fig.…”

“…10 A small diameter (0.20 mm) of the substrate was chosen in the present experiments in order to achieve a thicker diamond coating, inside which bonding forces could equalize and possibly surpass the thermal stress after termination of the deposition. Diamond deposition on Cu was a peculiar challenge in that copper does not react with the working atmosphere to form carbide (which would assist the growth and adhesion of a diamond coating) and because the thermal expansion coefficients of Cu and diamond are very different (which causes thermal stress in the coating, subsequent cracking and coating delamination upon cooling from deposition to room temperature).…”

“…10 The activating filament was formed as a large-diameter coil and the substrates were mounted through the coil centre, in order to obtain homogeneous and uniform diamond coatings on the thin cylindrical substrates, as well as to avoid complexity and expensiveness of the experimental apparatus (e.g., use of several filaments arranged symmetrically around the substrate, or the possibility of substrate rotation aside the filament). 10 The activating filament was formed as a large-diameter coil and the substrates were mounted through the coil centre, in order to obtain homogeneous and uniform diamond coatings on the thin cylindrical substrates, as well as to avoid complexity and expensiveness of the experimental apparatus (e.g., use of several filaments arranged symmetrically around the substrate, or the possibility of substrate rotation aside the filament).…”

NUCLEATION RATE OF DIAMOND FILMS ON WC-Co ALLOYS

“…However, various substrate compositions and substrate surface defects do have effect on the nucleation rate due to various substrates having different diffusion activation energies that are very correlated to the nucleation rate, just as it is known that under the certain deposition process conditions, the nucleation rates are different on various substrates. [4][5][6] As for the nucleation rate of diamond films on the hard metal (WC-Co) alloys, it is not reported how Co content and substrate surface defects will affect it. Therefore, an improved theoretical formula on the nucleation rate of diamond films on the hard metal alloys should be established in order to solve the problem, which would be useful for performing experiment research work more correctly.…”