Effect of chromium underlayer on the properties of nano-crystalline diamond films

Abstract

This paper investigated the effect of chromium underlayer on the structure, microstructure, and composition of the nano-crystalline diamond films. Nano-crystalline diamond thin films were deposited at high temperature in microwave-induced plasma diluted with nitrogen, on single crystal silicon substrate with a thin film of chromium as an underlayer. Characterization of the film was implemented using non-Rutherford backscattering spectrometry, Raman spectroscopy, near-edge x-ray absorption fine structure, x-ray diffraction, and atomic force microscopy. Nanoindentation studies showed that the films deposited on chromium underlayer have higher hardness values compared to those deposited on silicon without an underlayer. Diamond and graphitic phases of the films evaluated by x-ray and optical spectroscopic analyses determined consistency between the sp 2 and sp 3 phases of carbon in chromium sample to that of diamond grown on silicon. Diffusion of chromium was observed using ion beam analysis which was correlated with the formation of chromium complexes by x-ray diffraction. V

Metal dusting, carburization and diamond deposition on Fe–Cr alloys in CH4–H2 plasma atmospheres

“…The effect of Cr in ferrous alloys with a low fraction (<20 wt.%) of Cr has been studied, and the results show that Cr has little effect on diamond nucleation and growth [25,26]. Using Cr as interlayer was reported to be successful in improving the adhesion of diamond film on steels [11,14,15], primarily attributed to the formation of chromium carbides. On the other hand, other researchers concluded that Cr did not successfully function as a good interlayer for diamond deposition on ferrous alloys [27].…”

“…Finally, the high temperature plasma atmosphere * Corresponding author. [13][14][15][16][17][18][19][20], as well as surface modification by nitriding [21,22] or alloying [23,24].…”

Metallic Seed Nanolayers for Enhanced Nucleation of Nanocrystalline Diamond Thin Films

“…In numerous studies devoted to the growth of diamond thin films on ferrous and cemented carbide substrates, metallic interlayers were effectively employed to suppress the large uptake of carbon, to suppress the out-diffusion of highly reactive Fe and Co atoms, and to improve the adhesion of the diamond films on the substrate. − In addition, it has long been known that under conventional pretreatment conditions, such as manual scratching, the diamond nucleation densities on carbide-forming substrates (Si, Mo, W) are typically 1–2 orders of magnitude higher than those on substrates that do not form carbides (Cu, Au) . In this view, a number of recent studies focused on a precoating of silicon with thin (≤50 nm) metallic seed layers such as W, , Cr and Mo , followed by ultrasonic agitation with ND powders. These studies demonstrated a more uniform and denser nucleation of diamond during CVD.…”