Abstract
The role of NH3 for vertical alignment of CNTs was investigated. The direct cause of the alignment was a dense distribution of catalytic metal particles, but which was kept catalytically active during the growth process by NH3. This allows a dense nucleation of the CNTs, and consequently, assists vertical alignment through entanglement and mechanical leaning among the tubes. The CNTs grow in a base growth mode. Several evidences were presented including a direct cross‐sectional TEM observation. Since Ni is consumed both by suicide reaction and by capture in the growing tube, the growth stops when Ni is completely depleted. This occurs faster for smaller particles, and thus a longer growth results in thin bottom with poor adhesion.
Notes
Department of Materials Engineering, Chungnam National University, Taejon 305–764 Korea.
FED Team, Appl. Semicond. Dev. Dept., Adv. Micro‐electronics Res. Lab., ETRI, Taejon 305–350, Korea.
Member, KIDS.