The surface of polyimide ͑PI͒ films before/after plasma surface treatment using a remote-type modified dielectric barrier discharge was investigated to improve the adhesion between the PI substrate and the metal thin film. Among the plasma treatments of the PI substrate surface using various gas mixtures, the surface treated with the N 2 /He/SF 6 /O 2 plasma showed the lowest contact angle value due to the high CvO bondings formed on the PI surface, while that treated with N 2 /He/SF 6 showed the highest contact angle value due to the high C-F x chemical bondings on the PI surface. Specifically, when the O 2 gas flow was varied from 0 to 2.0 slm in the N 2 ͑40 slm͒/He͑1 slm͒/SF 6 ͑1.2 slm͒/O 2 ͑x slm͒ gas composition, the lowest contact angle value of about 9.3°w as obtained at an O 2 gas flow of 0.9 slm. And it was due to the high content of oxygen radicals in the plasma, which leads to the formation of the highest CvO bondings on the PI surface. When the interfacial adhesion strength between the Ag film and PI substrate was measured after the treatment with N 2 ͑40 slm͒/He͑1 slm͒/SF 6 ͑1.2 slm͒/O 2 ͑0.9 slm͒ followed by the deposition of Ag, a peel strength of 111 gf/mm was observed, which is close to the adhesion strength between a metal and the PI treated by a low pressure plasma.

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Multicrystalline silicon (mc-Si) was etched using a pin-to-plate-type remote dielectric barrier discharge, and the effect of adding NF 3 to N 2 (40 slm) and O 2 to N 2 (40 slm)/NF 3 (1 slm) on the characteristics of mc-Si etching and texturing was investigated. The addition of NF 3 at flow rates up to that of N 2 increased the mc-Si etch rate continuously by increasing the number of F radicals in the gas mixture. Furthermore, the addition of O 2 at flow rates of up to 400 sccm to N 2 (40 slm)/NF 3 (1 slm) further increased the mc-Si etch rate by more than two times (749.6 nm/scan, 0.25 m min −1), as compared with that without oxygen by the further dissociation of NF 3 caused by oxygen. In particular, the addition of O 2 to N 2 /NF 3 increased the surface roughness, due to the micromasking (local surface oxidation) effect and, by adding 600 sccm O 2 , a reflectance of 20-30% in the visible wavelength could be obtained due to the formation of optimal wave-type surface morphology.

The effect of the additional ac-bias voltage applied to the substrate on the characteristics of the SiO X deposited using modified remote-type atmospheric pressure plasma at room temperature was investigated for the gas mixture of hexamethyldisilazane/O 2 /He/Ar. The addition and increase of ac-bias voltage not only increased the deposition rate but also improved the characteristics of the deposited SiO X . With the increase of ac-bias voltage to the substrate, the oxygen percentage in the film increased while the carbon percentage is decreased by increasing Si-O-Si bonding and by decreasing the impurity such as -͑CH 3 ͒ X in the deposited film. In addition, the hardness and the surface smoothness of the deposited film were also increased with the increase of the ac biasing. The improvement of the film properties was related to the ion bombardment effect in addition to the increased gas dissociation by the additional power absorption, which was caused by the ac biasing of the substrate.

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