Abstract
This chapter focuses on the diamond nucleation mechanisms. The nucleation and early growth stages critically determine film properties, morphology, homogeneity, defect formation, adhesion, and the type of substrates that can be successfully coated. A high surface nucleation density may improve homogeneity of films and reduce formation of voids at the substrate/coating interface, leading to a better film/substrate adhesion. Diamond can grow homoepitaxially on a diamond surface without nucleation problems in Hot-filament chemical vapor deposition (HFCVD), Microwave Plasma-Assisted CVD (MW PACVD), and electron-cyclotron-resonance (ECR MW PACVD) from a variety of carbon sources. Diamond also nucleates easily on cBN to the identical crystal structure and the nearly identical lattice constant (mismatch 1.4%) and thermal expansion. The time needed to form a continuous film depends on not only growth parameters but also substrate materials and surface conditions, while the growth rate of a continuous film, itself, is independent of substrate materials and/or substrate surface conditions. Surface nucleation processes can be described with two quantities: surface nucleation density and surface nucleation rate. Nucleation density critically influences the thickness, crystallite size, homogeneity, morphology, adhesion, and surface roughness of deposited diamond films. Recent advances in experimental measurement methods make it possible to observe the nucleation and early growth stages, and in some cases in-situ or in vacua measurements.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.