Nanostructured sheet-like carbon, also called carbon nanoflakes (CNF), consists of petal-like graphite sheets with a thickness of less than 20 nm. These nanostructures are of interest for energy storage [1], electronic [2], and biological applications [3] due to their high surface area in the order of 1000–2000 m2/g [4], and their resistance to oxidation and high electrical conductivity [5]. Field emission cathodes based on arrays CNFs normally oriented to the substrate are considered promising materials for electrical applications [6], and can also be used in supercapacitors, since the high capacitance depends on the high specific area of conductive materials [4].
Previous works have reported the growth of CNF by hot filament chemical vapor deposition (HFCVD) [7] and by RF magnetron sputtering. In these methods, Hirase [8] proposed a growth mode of CNF related with the magnetron orientation and established that temperatures higher than 550 °C are not suitable for CNF. Zhu et al. [9] used an Ar atmosphere to grow CNF at temperatures higher than 800 °C, which has the advantage of needing neither catalytic processes nor special substrate preparation, as compared with HFCVD. This paper presents the growth of CNF by RF magnetron sputtering on silicon substrates using pure Ar plasma, but at lower temperatures than Hirase et al. [8] and Zhu et al. [9]. We study the influence of the substrate temperature and different deposition times on the carbon films.