Nanocrystalline Diamond Films Prepared with Different Diamond Seeding Processes of 4 Nm and 0.25 Μm Diamond Powders

Abstract

The growth of diamond films in metastable condition occurs in two steps: nucleation and growth of crystals. Studies have shown that the nucleation process is the most critical step and essential to optimize the properties of the diamond, but its understanding is still very limited. Furthermore, the nucleation process is directly related to the pretreatment applied to the surface of the substrate: cleaning the surface and seeding. When the substrate is silicon, it is cleaned with acetone and scratching with diamond particles dispersed in a suitable solvent followed by ultrasonic agitation (nucleation rate = 109part/cm2). However, research has demonstrated that the use of diamond nanoparticles (ND) prepared with the use of a powerful ultrasound (750W) provides nucleation density much higher (1012part/cm2) compared to that processed with larger size particles. This work demonstrates that diamond films prepared with ND different solutions exhibit differences in relation to diamond films prepared using diamond particle dispersed in an organic solvent. Morphological analysis and the quality of the films were evaluated by Scanning Electron Microscopy, Optical Perfilometry and Raman Scattering Spectroscopy.