Embedded vertically grown carbon nanotubes for field emission applications

Vertically aligned carbon nanotubes, embedded in titanium oxide, have been fabricated and their electron emission behavior has been characterized. The growth of carbon nanotubes was achieved using a dc plasma enhanced chemical vapor deposition method with a mixture of acetylene and hydrogen, and nickel was used as the catalyst layer. Titanium oxide, deposited using an atmospheric pressure chemical vapor deposition, was used to encapsulate the grown carbon nanotubes and the physical properties of the as-grown carbon nanotubes as well as the encapsulated structures have been investigated using scanning electron microscopy. By a sequential polishing and plasma ashing, it is possible to open up the top side of the encapsulated carbon nanotubes. Also by means of a reactive ion etching, carbon nanotubes are exposed with an inherent gate surrounding each one. This technique allows the evolution of individually processed nanotubes with no need of nanolithography. The emission of electrons from carbon nanotubes was examined and a preliminary field emission display was prepared.