Deposition and Characterization of Boron-Doped HFCVD Diamond Films on Ti, SiC, Si and Ta Substrates

Abstract

In the present investigation, titanium (Ti), silicon carbide (SiC), silicon (Si) and tantalum (Ta) samples with the same geometry are selected as substrates to deposite HFCVD boron-doped diamond films with the same deposition parameters, using trimethyl borate as the dopant. FESEM, EDS, Raman spectroscopy and Rockwell hardness tester are used to characterize as-deposited boron-doped diamond (BDD) films. The FESEM micrographs exhibit that the film deposited on Si substrate presents the best uniformity and that on Ti substrate has smallest grain size and film thickness, with titanium element detected in the EDS spectra. Moreover, it’s speculated by indentation test that the adhesive strength between the BDD films and different substrates can be order as SiC>Ta>Ti for the different thermal expansion coefficient gaps between the substrate and diamond, and the hardness of the BDD coated samples measured using Rockwell hardness tester can also be order as SiC>Ta>Ti due to the different hardness of substrate materials. Finally, similar and representative characterization for BDD films is obtained from the Raman spectra for all the BDD films on different substrates.

Rhenium alloys as ductile substrates for diamond thin-film electrodes

“…For example, diamond films grow conformally on high-temperature materials that pre-form a carbide interfacial layer to enhance film adhesion, e.g. , tungsten and molybdenum, whereas coatings of non-carbide forming materials have often required pre-deposition of carbide-forming interlayers or altering of growth conditions, which may unavoidably compromise the diamond film quality [1, 6, 7, 9-20]. Recent interest in applying conductive diamond as an implantable electrode in biomedical devices, for use either in vitro (tissue in a dish)[7, 21, 22] or in vivo (implantation in a live animal),[1, 23] has brought renewed attention to the need for alternatives to traditional high-temperature substrates.…”