Synthesis of nanocrystalline diamond films using microwave plasma CVD

• Published in: Diamond and related materials Vol. 10; no. 9; pp. 1588 - 1591
• Main Authors: Yoshikawa, Hiromichi, Morel, Cedric, Koga, Yoshinori
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2001; Elsevier
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diamond films; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microstructure; Nanoscale materials and structures: fabrication and characterization; Physics; Raman spectroscopy; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Microstructure; Raman spectroscopy; Diamond films; Atomic force microscopy; Raman spectra; Films; Diamonds; Roughness; Surfaces; Crystal growth from vapors; XRD; Hardness; Experimental study; Nonmetals; SEM; Nucleation density; PECVD; Nanocrystal
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(01)00414-9

Diamond is one of the most valuable materials for the industrial applications because of its excellent properties including high hardness, with good electrical insulation and thermal conductivity. Mechanical polishing processes of diamond are difficult and very costly. To limit those costs, it is reasonable to think that the surface roughness of the as-grown diamond film should be as small as possible. In this study, a nanocrystalline diamond film was synthesized on a 4-inch Si wafer at 923 K and methane concentration of 10 vol.%, (H 2/CH 4=100/10 sccm) using a microwave plasma CVD system. In order to increase the nucleation density, the substrate was pretreated by dry scratch method with diamond powder of two sizes (250 nm and 5 nm). The nucleation density was approximately 1×10 11 cm −2. The grown diamond films were analyzed by Raman spectroscopy and X-ray diffraction (XRD). The grain size was observed to be approximately 10 nm by FE-SEM observation. Surface roughness was measured as Rms=8.4 nm by atomic force microscope (AFM). The as-grown properties of those nanocrystalline diamond films were almost efficient for tribological and the optical applications.