Study of the Chemical Vapor Deposition of Nano-Sized Carbon Phases on {001} Silicon

• Published in: Materials Vol. 16; no. 22; p. 7190
• Main Authors: Milenov, Teodor, Trifonov, Dimitar, Kalchevski, Dobromir A., Kolev, Stefan, Avramova, Ivalina, Russev, Stoyan, Genkov, Kaloyan, Avdeev, Georgi, Dimov, Dimitar, Karaivanova, Desislava M., Valcheva, Evgenia
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.11.2023
• Subjects: Argon; Carbon; carbon phases; Chemical synthesis; Chemical vapor deposition; Decomposition; diamond; Diamond-like carbon; Diamond-like carbon films; Gas flow; Geometry; Graphene; Graphite; Hydrocarbons; Lasers; Molecular dynamics; Morphology; Nanocrystals; nanomaterials; Polytypes; Scanning electron microscopy; Silicon; Silicon carbide; Silicon dioxide; Silicon substrates; Temperature; thin films; Bulgaria; United Kingdom; United Kingdom > UK; United States > US
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16227190

Different nano-sized phases were synthesized using chemical vapor deposition (CVD) processes. The deposition took place on {001} Si substrates at about 1150–1160 °C. The carbon source was thermally decomposed acetone (CH3)2CO in a main gas flow of argon. We performed experiments at two ((CH3)2CO + Ar)/Ar) ratios and observed that two visually distinct types of layers were deposited after a one-hour deposition process. The first layer type, which appears more inhomogeneous, has areas of SiO2 (about 5% of the surface area substrates) beside shiny bright and rough paths, and its Raman spectrum corresponds to diamond-like carbon, was deposited at a (CH3)2CO+Ar)/Ar = 1/5 ratio. The second layer type, deposited at (CH3)2CO + Ar)/Ar = a 1/0 ratio, appears homogeneous and is very dark brown or black in color and its Raman spectrum pointed to defect-rich multilayered graphene. The performed structural studies reveal the presence of diamond and diamond polytypes and seldom SiC nanocrystals, as well as some non-continuously mixed SiC and graphene-like films. The performed molecular dynamics simulations show that there is no possibility of deposition of sp3-hybridized on sp2-hybridized carbon, but there are completely realistic possibilities of deposition of sp2- on sp2- and sp3- on sp3-hybridized carbon under different scenarios.