3INPE, LAS, Caixa Posta 515, 12212-970 – Sao José dos Campos, SP, Brazil.

Diamond like carbon (DLC) films have been studied intensively due to their physical-chemical properties, namely, high density, high electrical resistivity, chemical inertness. These properties suggest vast opportunities for electronic applications of DLC, such as intermetal dielectric and passivation layer. For microelectronic purposes, these films are usually obtained by PECVD techniques using CH₄ and C₂H₂ gases as carbon and hydrogen sources. Sputtering is another common technique used to produce not only hydrogenated (a-C:H) carbon films, but also non-hydrogenated (a-C) ones. The a-C films are usually produced by sputtering of a carbon target with positive ions of an argon plasma. Usually, a-C:H sputtered films are produced by adding hydrogen gas in the discharge. The hydrogen incorporation in the film promotes stabilization of the sp³ bonds, changing the characteristics of the film. In this work, CH₄ was used, instead of H₂, as an alternative source of hydrogen in a reactive sputtering system to growth DLC films on silicon. The behavior of the D and G bands and the ratio of integral peak areas (I_D/I_G) of the Raman spectra has been used to determine the maximum limit of the CH₄ content on the discharge to produce DLC films. A complementary analysis of the atom bonding configuration has been done with Fourier Transform Infrared Spectroscopy (FTIR). Electrical parameters of the films –resistivity, dielectric constant and breakdown field- have been obtained from the I vs V and C vs V curves.

Preferred presentation: poster