Plasma CVD characterization of nanocarbon film growth

Abstract

We report on the characterization of d.c. discharge plasma-enhanced chemical vapour deposition of nanocarbon film materials in a hydrogen-methane gas mixture. The effects of the gas composition and pressure on the current-voltage characteristics and optical emission spectra of the discharge plasma are studied. By varying the parameters we obtain various carbon thin-film materials, the structure and composition of which are characterized qualitatively by Raman spectroscopy and electron microscopy. The data obtained by optical emission spectroscopy show the presence of H, H 2 , CH and C 2 activated species in the discharge plasma. We assume that C 2 dimers play a decisive role in nanostructured graphite-like carbon film formation and carbon condensation in the gas phase.

Plasma techniques for nanostructured carbon materials synthesis. A case study: carbon nanowall growth by low pressure expanding RF plasma

“…The literature is abundant in results describing the plasma emission during nanostructured carbon deposition [26,64]. Among the species considered to play a role in the deposition and nanostructuring process are C 2 dimmers which are presumed to insert into the carboncarbon bonds and to form critical nuclei that evolve toward two-dimensional graphite-like sheets [64], CH carbon radicals which mostly contribute to the deposition of amorphous carbon and the H atoms which are supposed to activate the surface dangling bonds and etch away the amorphous carbon phase [65]. Therefore, we focused our investigation on these species.…”

Efficient surface-conduction field emission electron sources from tin oxide film

“…Further, in the field of vacuum micro-and nano electronics [4e7], field emitter arrays (FEAs), integrated with microscale and nanoscale field-emission-type electron sources, have been developed for various applications using the advantage of field emission electron beams, such as field emission displays [8,9], field emission lamps [10,11], small X-ray sources [12e14], high-frequency devices [15], and electric power switching devices [16,17]. To date, semiconductor nanofabrication processes have been used to fabricate different types of field emission electron sources to achieve better FE characteristics and stability, such as the Spindt type [18] and Si type [19] which were suitable for mass production, normal-gate type [20,21], under-gate type [22,23], planar-gate type [24,25] and surface-conduction field emission electron sources [26e28].…”