Effect of substrates and underlayer on CNT synthesis by plasma enhanced CVD

Due to their unique thermal, electronic and mechanical properties, carbon nanotubes (CNTs) have aroused various attentions of many researchers. Among all the techniques to fabricate CNTs, plasma enhanced chemical vapor deposition (PECVD) has been extensively developed as one growth technique to produce vertically-aligned carbon nanotubes (VACNTs). Though CNTs show a trend to be integrated into nanoelectromechanical system (NEMS), CNT growth still remains a mysterious technology. This paper attempts to reveal the effects of substrates and underlayers to CNT synthesis. We tried five different substrates by substituting intrinsic Si with high resistivity ones and by increasing the thickness of SiO₂ insulativity layer. And also, we demonstrated an innovative way of adjusting CNT density by changing the thickness of Cu underlayer.