Growth rate enhancement and morphology engineering of diamond films by adding CO.sub.2./sub. or N.sub.2./sub. in hydrogen rich gas chemistry

0432636 - FZÚ 2015 RIV US eng J - Journal Article
Ižák, Tibor - Davydova, Marina - Varga, Marián - Potocký, Štěpán - Kromka, Alexander
Growth rate enhancement and morphology engineering of diamond films by adding CO₂ or N₂ in hydrogen rich gas chemistry.
Advanced Science, Engineering and Medicine. Roč. 6, č. 7 (2014), s. 749-755. ISSN 2164-6627
R&D Projects: GA MPO FR-TI2/736; GA ČR GAP205/12/0908; GA ČR(CZ) GP14-16549P
Institutional support: RVO:68378271
Keywords : microwave plasma CVD * diamond growth * nitrogen * carbon dioxide * growth rate * SEM
Subject RIV: BM - Solid Matter Physics ; Magnetism

Diamond films and structures were grown by MWCVD. We show that increasing of CH4 concentration in the gas mixture up to 8% results almost in a linear increasing of growth rate (up to 900 nm/h). Unfortunately, diamond film quality decreases due to the dominance of sp2 carbon phases, as confirmed by Raman measurements. Furthermore, increasing of CH4 concentration also enhances spontaneous nucleation. Addition of N2 and CO2 into CH4/H2 gas mixture also enhances the growth rate. Nitrogen shifts the film morphology from micro- to nanocrystalline. For enough high methane concentration (>5% CH4), increasing of nitrogen further shifts the diamond growth in formation of nanowire like structures. In opposite to the nitrogen addition, adding CO2 to the gas mixture improved the film quality. In this case, a higher methane concentration can be used to increase the growth rate while keeping good enough film quality.
Permanent Link: http://hdl.handle.net/11104/0237014