Journal of Alloys and Compounds 478 (2009) 474–478 Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: www.elsevier.com/locate/jallcom A comparative study of Si–C–N films on different substrates grown by RF magnetron sputtering A.S. Bhattacharyya a,b,∗ , S.K. Mishra a , S. Mukherjee b , G.C. Das b a National Metallurgical Laboratory, Jamshedpur 831007, India b Jadavpur University, Kolkata 700032, India article info Article history: Received 23 July 2008 Received in revised form 10 November 2008 Accepted 16 November 2008 Available online 3 December 2008 Keywords: Si–C–N RF sputtering Substrate effect abstract Si–C–N nanocomposite thin films were deposited on industrially important substrates like silicon (1 0 0), borosilicate glass, and stainless steel (304SS) by radio frequency (RF) magnetron sputtering. The microstructural characterization was carried out by transmission electron microscopy (TEM) showing localized -C 3 N 4 in amorphous Si–C–N matrix, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The thermal mismatch occurring between the substrate and the coating resulted in variation in deposition rate, roughness and other mechanical properties like hardness and adhesion for the three different substrates. Both microindentation and nanoindentation were performed to estimate the hardness of the coatings. Scratch tests were used for the adhesion studies. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Si–C–N has been a very important nanocomposite mate- rial showing promising combination of properties [1] Si–C–N nanocomposite coatings exhibit improved properties compared to conventional coatings in terms of better thermal conduc- tivity, thermal stability, hardness, tunable band gap, chemical inertness, wetting behaviour and wear resistance [2–6]. Due to these unusual combinations of properties, they have a large range of applications, e.g. wear resistant coatings for automo- tive industry, microelectronic mechanical system (MEMS) device fabrication, high temperature semiconducting and optoelectronic devices [7–10]. Si–C–N also finds application in biological purification step by producing pure gDNA [11]. Nanocomposites consisting of precursor-derived Si–C–N ceramics incorporated with carbon nan- otubes (CNTs) were successfully prepared by casting a mixture of CNTs and a liquid precursor polymer followed by cross-linking and thermolysis [12]. The high temperature behaviour of Si–C–N ceramics has been thermodynamically calculated using CALPHAD software [1]. A study of the relationship between the chemical and structural properties with terminological properties of sputtered Si–C–N films have been carried out, where the hardness of the film ∗ Corresponding author at: NML, Jamshedpur, India. Tel.: +91 657 2271709 14; fax: +91 657 2270527. E-mail address: 2006asb@gmail.com (A.S. Bhattacharyya). has been found to vary depending upon the position in the Si–C–N phase diagram [5]. Several methods for the fabrication of amorphous and crys- talline Si–C–N films are reported in the literature. Both crystalline and amorphous or nanostructured Si–C–N compounds have been prepared. They are produced in bulk form by pyrolysis of organometallic polysilazane precursors, where polymer to ceramic transformation takes place [11,13,14]. The polymer impregnation and pyrolysis (PIP) process was used to prepare a mullite interphase of C/Si–C–N composites in order to provide an acceptable oxidation protection of these composites [15]. Thin film depositions of Si–C–N have been carried out by plasma and ion assisted deposition, chemical vapour deposition, mag- netron sputtering, microwave and electron cyclotron resonance plasma enhanced chemical vapour (ECRPECVD), ion implantation, pulsed laser deposition and Rapid thermal chemical vapour depo- sition (RTCVD) [2–10]. At substrate temperatures below 1000 ◦ C, amorphous Si–C–N films are reported to be deposited, while higher temperatures produced crystalline composite films of - and - Si 3 N 4 and - and -SiC [6]. Microhardness increase and promising field emission properties were obtained from CGed films in com- parison with monolithic SiC and SiN x films deposited by PECVD [16]. Si–C–N thin films with tailored stoichiometries on the tie line SiC–Si 3 N 4 have been produced by several fold ion implantation and by a combination of RF magnetron sputtering and ion implantation [17]. These high purity thin films have been heat treated at 1250 ◦ C under high vacuum conditions using an electron beam annealing system to enable crystallization and/or phase formation. The for- mation of an amorphous network of mixed Si(C,N) 4 tetrahedrons 0925-8388/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2008.11.105