Boron-Carbon-Nitrogen (BCN) films are deposited on Si (100) substrates by RF sputtering with a mixture of N2 and Ar gases using a target of graphite combined with semi-circled B4C. The compositional analysis is carried out by energy dispersive X-ray spectroscopy (EDX). The microstructure and mechanical properties are examined by fourier transformation infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and nanoindentation measurements. The results of FT-IR show the presence of h-BN bonds and evidences in support of B-C, C-N, C=N, C=C and C≡N bonds. In additon, the C content of the films can be changed in the range of 13−45% according to the sample position. Hardness of the films is increased from 8 to 18GPa with increasing C content. After thermal annealing at 600ºC in air, h-BN bonds in the films are not affected significantly although the samples are oxidized. However, the hardness of the samples is abruptly reduced to 4GPa for all samples. From AFM observation, it is assumed that the development of the void-like structure is responsible for the reduction in hardness.
The hydrogenation of brightener 2-butyne-1,4-diol at nickel electroplating from a Watts-type bath was investigated. The amount of hydrogen gas evolved during electroplating was in-situ evaluated quantitatively on the basis of buoyancy produced by hydrogen gas using an electric balance. The variation of the internal strain in nickel films plated with the addition of 2-butyne-1,4-diol was measured using a resistance wire-type strain gauge placed on the reverse side of the copper substrate. The hydrogenation of 2-butyne-1,4-diol progressed easily on as-deposited nickel substrate compared with the commercial copper and nickel substrates, and the hydrogenation of 2-butyne-1,4-diol was always preferred to the formation of hydrogen gas during nickel electroplating. The 2-butyne-1,4-diol adsorbed on as-deposited nickel electrode was hydrogenated catalytically by hydrogen co-deposited with nickel on the electrode. The hydrogenation of 2-butyne-1,4-diol might bring about the formation of internal tensile stress in the nickel deposits during electroplating.
We investigated thermal expansion properties of Ni-Fe alloy electrodeposits, which are anticipated for use as low thermal expansion materials. Thick and crack-free Ni-Fe alloy electrodeposits with 25 to 58mass% Fe contents were obtained from sulfate/chloride electrolytes with additives, saccharin and malonic acid. The linear expansion coefficients of the electrodeposited Ni-Fe alloy pipes reduced with increasing Fe contents as melted alloys. For the Ni-58mass%Fe alloy electrodeposits, the linear expansion coefficient exhibited 8.6×10−6/ºC for the as-plated specimen and approximately 7×10−6/ºC for the alloys annealed above 350ºC.