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This report describes a helicity-selective photoreaction of single-walled carbon nanotubes (SWNTs) with disulfide in the presence of oxygen. The SWNTs were characterized using absorption, photoluminescence (PL), Raman, and X-ray photoelectron spectroscopy, scanning electron microscopy, and current-voltage (I-V) measurements. Results showed remarkable helicity-selective (metallic SWNTs/semiconducting SWNTs and diameter) functionalization of SWNTs. The reaction rate decreases in the order of metallic SWNTs > semiconducting SWNTs and small-diameter SWNTs > large-diameter SWNTs. Control experiments conducted under various experimental conditions and ESR and femtosecond laser flash photolysis measurements revealed that the helicity-selective reaction proceeds via a photoinduced electron transfer reaction. The PL and I-V measurements showed that the photoreaction is effective not only to control SWNT conductivity but also for the band gap modulation of semiconducting SWNTs.

Ruthenium (Ru) films were deposited by liquid source chemical vapor deposition using bis-(ethylcyclopentadienyl)ruthenium (Ru(C2H5C5H4)2). The crystalline structure, resistivity and residual impurities in the Ru films were investigated. The Ru films were polycrystalline and had a columnar structure; they showed a low resistivity of about 20 µΩ cm, which is sufficiently low for them to be used as capacitor electrodes.

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Ru films were fabricated by chemical vapor deposition using Ru(C 5 H 5 ) 2 and O 2 . The deposition of Ru film was controlled by the surface reaction kinetics as the rate limiting step with activation energy of 2.48 eV below 250 • C and by the mass transport process above 250 • C. Ru films had a polycrystalline structure and showed low resistivity of about 12 µ cm. Ru films deposited at 230 • C showed excellent step coverage. We applied Ru films prepared by chemical vapor deposition to the bottom electrode of a Ba 0.25 Sr 0.75 TiO 3 capacitor and obtained good electrical characteristics.