GROWTH OF CARBON NANOTUBES IN ETCHED ION TRACKS IN SILICON OXIDE ON SILICON

Abstract

Carbon nanotubes (CNTs) were selectively grown in etched ion tracks in SiO 2 layers on Si . For this sake, Ni -catalyst nanocrystals were initially deposited within the ion tracks by galvanic deposition. The characteristics of plasma-enhanced chemical vapor deposition (PECVD)- and thermal chemical vapor deposition (TCVD)-grown CNTs, such as structural details and length distribution, were investigated. In addition, field emission properties were studied. The analysis revealed that the emerging PECVD-grown CNTs were of cylindrical and/or conical shape and usually had diameters as large as the etched tracks. The exponential length distribution of these CNTs can be well understood by applying a simple defect-growth model. For contrast, many narrow and curled CNTs were found to cluster in spots well separated from each other, after applying TCVD instead of PECVD. The Raman investigations of PECVD-grown CNTs showed that Si – O – C and Si – C phases had formed during the growth of the CNTs. These ion-track-correlated PECVD-grown CNTs open the way for the production of novel 3D nanoelectronic devices based on the TEMPOS concept. These structures are also excellent candidates for experiments on channeling in CNTs. Application as field emitting devices, however, appears unfavorable due to poor mean-field enhancement factors and insufficient stability.