Effect of the on/off cyclic modulation time ratio of C2H2/H2 flow on the low temperature deposition of carbon nanofilaments.
Low temperature (less than 600 degrees C) deposition of carbon nanofilaments (CNFs) could be achieved on the silicon oxide substrate by thermal chemical vapor deposition system. We used Fe(CO)5 as the catalyst precursor for CNFs formation. For the enhancement of CNFs formation density, the source gas flow was intentionally manipulated as the cyclic on/off modulation of C2H2/H2 flow during the initial deposition stage. The CNFs formation density on silicon oxide substrate could be much enhanced by the cyclic modulation process having the higher growing/etching time ratio (180/30 s). Furthermore, the lattice structures of CNFs developed into carbon nanotubes at the higher growing/etching time ratio (180/30 s) case. The solely hydrogen gas feeding (C2H2 flow off) time during the initial deposition stage seems to play an important role for the variation in the CNFs formation characteristics by the cyclic modulation process.
Department of Electronic Materials Engineering, Silla University, Busan 617-736, Korea.
Kwang-Duk
KD
Kim
Sung-Hoon
SH
Kim
Nam Seok
NS
Kim
Dong-Uk
DU
Kim
D000114:Acetylene / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D044085:Microfluidics / Q000379:methods*; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*
D005740:Gases; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; C009495:titanium dioxide; D006859:Hydrogen; D014025:Titanium; D000114:Acetylene