The Formation of Silicon Carbide in the SiCx Layers (x = 0.03–1.4) Formed by Multiple Implantation of C Ions in Si

Abstract

Promising application of thin-film technology is the synthesis of SiC, possessing such valuable properties as high hardness (33400 Mn/m2), chemical resistance, high melting point (2830°C), wide bandgap (2.3–3.3 eV), etc (Lindner , 2003). Unfortunately, since it is still difficult to grow SiC material of crystalline quality to meet requirements for a large scale industrial application, small-size and high-cost SiC wafers severely limit their applications at present (Liangdeng et al., 2008). Doped with different impurities, silicon carbide is used in semiconductor technology (Yаn et al., 2000; Chen et al., 2003). Field-effect transistors, diodes and other electronic devices based on SiC have several advantages compared to similar silicon devices. Among them, the opportunity to work at temperatures up to 600°C, high speed and high radiation resistance. A large number of polytypes of SiC makes it possible to create heteropolytype structures (Lebedev et al., 2001, 2002a, 2005) to form a defect-free, near-perfect contacts with unusual electronic properties (Fissel et al., 2001; Lebedev et al., 2002b; Semenov et al., 2010). Diode structures have been established (Lebedev et al., 2002b), in which the value of uncompensated donors Nd−Na was (1.7−2)×1017 сす-3 in the layer (n) 6H-SiC and acceptors Na−Nd ~ 3×1018 сす-3 in the layer (p) 3C-SiC. In the spectrum of the electroluminescence of diodes revealed two bands with maxima h┥max ≈ 2.9 eV (430 nm) and 2.3 eV (540 nm), close the band gaps of 6H-and 3C-SiC. Currently, using the methods of vacuum sublimation (Savkina et al., 2000), molecular beam epitaxy (Fissel et al., 1996), the epitaxial and heteropolytype layers based on the cubic 3C-SiC and two hexagonal 6H-SiC, 4H-SiC on substrates of SiC, are grown. By chemical vapor deposition (CVD) (Nishino et al., 2002) are grown heteroepitaxial layers of 3C-SiC on substrates of Si. At the temperatures below 1200°C there are conditions for the growth of both polyand nanocrystalline SiC with different degrees of crystallinity and structure of the cubic polytype 3C-SiC. Such conditions were realized in the magnetron sputtering (Kerdiles et al., 2000; Sun et al., 1998), laser ablation (Spillman et al., 2000) and plasma deposition (Liao et al., 2005), plasma-enhanced chemical vapor deposition (George et al., 2002; Pajagopalan et al., 2005), molecular beam epitaxy (Fissel et al., 2000). At temperatures below 1500°C in the direct deposition of carbon and silicon ions with an energy of ~100 eV, the growth of nanocrystalline films with a consistent set of the polytypes 3C, 21R, 27R, 51R, 6H is possible (Semenov et al., 2008, 2009, 2010). Photoluminescence spectrum from the front surface of the nanocrystalline film