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Abstract: Microcrystalline diamond has been successfully synthesized in a low-pressure inductively coupled plasma using di-t-alkyl peroxide. Di-t-alkyl peroxides are thermally decomposed into acetones and methyl radicals, which presumably serve as precursors for the formation of diamond on the silicon substrate at 943 K and 993 K. The deposits on the substrate were examined by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. It was found that the deposits contained a microcrystalline diamond phase even at a low pressure of 11 Pa. Diamond formation over a large area in low-pressure plasmas has been demonstrated by the present novel diamond deposition process using di-t-alkyl peroxide thermally decomposed as a feed gas. [Copyright &y& Elsevier]

Sp2-bonded boron nitride (BN) films are deposited on Ni and Si substrates with mean ion impact energies between a few eV and around 100 eV by surface-wave plasma enhanced chemical vapor deposition and their electrical insulation characteristics are examined for temperatures up to 300 °C. The overall crystallinity and order of sp2 structure in the films increase with decreasing ion energy, while the mass density becomes as high as sintered hexagonal BN only when the ion energy is above ∼50 eV. For a given temperature, the electrical resistivity of the films measured for metal-BN-metal structures increases with decreasing ion energy, and hence increasing crystallinity and order of sp2 structure, almost independent of mass density. A decrease in resistivity with temperature is small below 150 °C, then becomes large above 150 °C with a drastic increase in apparent activation energy for carriers, which is attributed to generation and transport of the carriers that get over higher barrier heights associated with stronger ion impact. [ABSTRACT FROM AUTHOR]

Low temperature annealing of p- and n-type Si paste films consisting of nanocrystal Si particles coated on Al substrates was investigated for application to low cost large-area electronic devices such as solar cells. This process based on aluminum-induced-crystallization enabled one to enhance recrystallization of the Si paste films with reduction of residual tensile stress while suppressing oxidation greatly even at low temperatures (400–550 °C), as confirmed by Raman spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. pn homo-junction diodes were fabricated successfully using a p/n-type double layer Si paste film and even an n-type single layer Si paste film on Al substrates by annealing at temperatures less than 550 °C. The current-voltage characteristic of the diode using a p/n-type double layer Si paste film showed rectification with the on/off current ratio of about 3200 and the reverse current density of the order of 10−9 A/cm2 at room temperature. [ABSTRACT FROM AUTHOR]