Room-Temperature Growth of SiC Thin Films by Dual-Ion-Beam Sputtering Deposition

Abstract

Silicon carbide (SiC) films were prepared by single and dual-ion-beam sputtering deposition at room temperature. An assisted Ar + ion beam (ion energy Ei = 150 eV) was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si-C bond in the film has increased. At the same time, the excess C atoms or the size of the sp 2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si-C bond.

Tailoring of stoichiometry and band-tail emission in PLD a-SiC thin films by varying He deposition pressure

“…The bands lying within 700-1100 cm −1 are much broad which indicates the presence of high structural disorder in SiC bonds and hence it is attributed to optical Raman modes of a-SiC. The third band (1300-1600 cm −1 ) is attributted to Raman modes resulting due to largely disordered C-C bonds [41]. The intensity of C-C peak w.r.t Si-Si/Si-C (acoustic mode) peaks increased with increasing He pressure till 1 mbar followed by sudden disappearance of C-C band in the film fabricated at 5 mbar of He pressure.…”

“…The peaks within broad bands in the regions of 200-700 cm −1 which corresponds to acoustic (LA and TA) Raman modes of a-SiC overlapped with Raman modes (TO, LO, LA and TA) of a-Si marked as region I[38,39], while those within spectral region 700-1200 cm −1 corresponding optical Raman modes of a-SiC are marked as region II and peaks within 1300-1600 cm −1 corresponding to C-C bonds are marked as region III. The third broadband region marked as III in the figures, is attributed to Raman modes arising from amorphous C containing mixed phase of sp 3 -sp 2 with random covalent network of tetrahedral-trigonal bonds characterised by distorted bond angles and bond lengths[41]. For the sample deposited under vacuum ~ 10 −6 mbar (Fig.2a), all the prominent peaks were tabulated in Table1, where peak corresponding to TO mode of a-Si at 498 cm −1 was most intense[42].…”