**3.1 Structural investigations of RF sputtered SiC over Si(111)**

In order to investigate the structural changes after 80 keV argon ion sputtering in SiC/Si(111) surfaces, we have performed Raman scattering in backscattering geometry at room temperature.

**Figure 1** displays the room temperature (RT) first-order Raman spectra acquired from a bare Si(111) substrate, the as-deposited SiC film and 80 keV argon ion sputtering at various argon ion fluences, respectively.

**Figure 1(a)** reveals that Raman spectra of Si(111) consists of one sharp peak at 520 cm−1 corresponding to first-order transverse optical phonon (1TO) vibrations of crystalline silicon [1–4]. In addition, the presence of second-order transverse optical mode (2TO) at 929–1027 cm−1 has been identified. This validates the crystalline nature of the surface layers in Si(111).

**Figure 1(b)** exhibits that Raman spectra of SiC RF sputtered over Si(111) display the presence of longitudinal and transverse phonon modes of Si-C bonds in SiC at wavenumber of 972 and 796 cm−1, respectively. Generally, the 3C-SiC single crystal has these two strong phonon modes corresponding to longitudinal optical (LO) and transverse optical (TO) vibrations, whose Raman shifts are 972 and 796 cm−1, respectively [1–4]. The presence of these two phonon modes but with reduced intensity and board linewidth in Raman spectra in **Figure 1(b)** confirms that the SiC layers, analyzed in this work, consist mainly of cubic poly-type structure [1–5]. Due to the
