Methane CH4
Methane is the most conventional carbon precursor for the chemical vapor deposition (CVD) of carbon, graphite, diamond and carbide thin films. [44, 1]
Methane CH4 for nanocrystalline carbon by CVD
Nanocrystalline carbon thin films with or without sulfur doping (n-C or n-C:S) have been grown on Mo substrates from the gas mixtures of methane CH4, hydrogen and varying concentration of H2S by hot-filament chemical vapor deposition (HFCVD). The films were characterized by Raman spectroscopy (RS), spectroscopic phase modulated ellipsometry (SPME) from near IR to near UV (1.5-5.0 eV) obtaining their vibrational frequencies and pseudodielectric function, respectively. According to Raman and ellipsometry results, the average size of nanocrystallites in n-C:S films reduced with increasing sulfur doping, in agreement with AFM measurements. The bandgap of n-C:S decreased with increasing H2S concentration, indicating the enhancement of midgap states and sp2 C network, m agreement with RS results.[[i][PS1] ]
[i]S. Gupta, B. R. Weiner and G. Morell, MRS Proceedings / Volume 703 / 2001, DOI: http://dx.doi.org/10.1557/PROC-703-V11.9 , “Optical Characterization and Modeling of Sulfur Incorporated Nanocrystalline Carbon Thin Films Deposited By Hot Filament CVD”
CH4 for diamond films by PECVD
CH4/H2 plasma has been applied for the growth of diamond (d-C) films by microwave plasma CVD on platinum (Pt) foils (as-received or specially processed with (111) domains), bulk single-crystal Pt (111), and single-crystal Pt(111) films on SrTiO3(111). Diamond films grown on the (111) areas of the substrates had azimuthally aligned (111) faces, with significant spontaneous coalescence developed between neighboring faces (SEM). Diamond crystals had an epitaxial relationship with Pt, with (111) crystal at a diamond film surface containing an extremely low dislocation density (~ 108/cm2), as determined by XTEM. [[i][PS1] ]
[i] Takeshi Tachibana, Yoshihiro Yokota, Koichi Miyata, Takashi Onishi, Koji Kobashi, Masayoshi Tarutani, Yoshizo Takai, Ryuichi Shimizu, and Yoshihiro Shintani
Phys. Rev. B 56, 15967 – Published 15 December 1997
DOI: http://dx.doi.org/10.1103/PhysRevB.56.15967
Diamond films heteroepitaxially grown on platinum (111)