We discuss the central issues to be addressed for realizing carbon nanotube (CNT) future electronic devices. We focus on the selective growth, electron energy bandgap engineering and device integration. We have introduced nanotemplate to control the selective growth, length and diameter of CNT. Vertically aligned CNTs are synthesized for developing a vertical CNT-field effect transistor (FET). The ohmic contact of the CNT/metal interface is formed by rapid thermal annealing. Diameter control, synthesis of y-shape CNT and surface modification of CNT open the possibility for energy band gap modulation. Y-junction singlewall carbon nanotubes (SWNTs) are synthesized using controlled catalysts by chemical vapor deposition. Mo-doped Fe nanoparticles supported by aluminum oxide particles are used as catalysts for the growth of Y-junction singlewall carbon nanotubes. Most of Y-junctions consist of three individual SWNTs with different diameters. Radial breathing mode peaks in Raman spectra show that our sample has both metallic and semiconducting nanotubes, indicating the possible formation of Y-branching with different electrical properties. The Surface modification of the carbon nanotubes plays an important role for their utilization in various applications. The surface of grown nanotubes was modified and the wettability on nanotubes was investigated. This functionalisation tends to change the surface of nanotubes into hydrophilic thus increasing its sensitivity. The electrical characterization of these modified nanotubes was performed since it is expected that by adapting analytes onto the modified nanotubes, the electric transport property of CNT may be changed. A concept of ultra-high density transistor based on the vertical-CNT array and nonvolatile memory based on the top gate structure with oxide-nitride-oxide charge trap is also presented.
Web Page: faculty.eng.fiu.edu/~wchoi
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