Fabrication of Si–C–N compounds in silicon carbide by ion implantation
Introduction
Si–C–N materials are of considerable interest as high temperature engineering materials combining the properties of silicon carbide and silicon nitride [1]. A number of experimental and theoretical investigations of the electronic and structural properties of the silicon carbonitride films have been carried out using different growth techniques for the Si–C–N film synthesis. Ion implantation provides a practical method of synthesis of Si–C–N compounds and has been successfully employed to produce Si–C–N composite layers in silicon [2], [3]. The combination of carbon and nitrogen implantation in silicon has been investigated to produce a silicon carbonitride layers with tailored stoichiometries [2]. It has been shown that Si–C–N films with carbon concentration above the solubility limit in Si3N4 remained amorphous after annealing at 1250 °C. IR and XPS analysis of the Si–C–N films has suggested the formation of an amorphous network of mixed Si(C, N)4 tetrahedrons.
Ion implantation has only rarely been applied to the fabrication of Si–C–N layers in silicon carbide material. Early examples studied nitrogen implantation in silicon carbide at room temperature [4]. It has been reported that nitrogen implantation into SiC at room temperature associated with the formation of SixCyNz composite. McHargue et al. [5] have shown the possibility of more significant replacement of carbon by nitrogen atoms during nitrogen implantation in silicon carbide at high temperatures. Miyagawa et al. [6] have observed β-Si3N4 crystallites formation in a polycrystalline β-SiC after nitrogen implantation at 1100 °C. The ion implantation with nitrogen ions at room temperature into 70% SiC–C films has also been reported to form SiCyNz compound [7]. In this paper we study the structural, chemical and bonding variations in silicon carbide by implanting nitrogen ions at high dose and high temperature.
Section snippets
Experimental
14N+ ions at 200 keV were implanted into the 4H silicon carbide wafers, using Varian300XP ion implanter. The dose of implantation was 1.4 × 1018 at. cm−2. During implantation the wafers were maintained at temperature of 650 °C. After the implantation, a silicon carbide epitaxial layer (0.65 μm thick) has been deposited on as-implanted layer by CVD method at 1600 °C to produce structure for applications in new integrated devices. The resulted structure is shown in Fig. 1(a).
X-ray photoelectron
TEM imaging
The TEM image shown in Fig. 1(b) demonstrates the structure of the 4H-SiC film implanted at 200 keV with a nitrogen dose of 1.4 × 1018 at. cm−2 (14N+) and substrate temperature of 650 °C followed by the 4H-SiC epitaxial film deposition. The implanted region is clearly visible as a bright region with two dark defective regions. The bright region corresponds to the projected range depth of nitrogen. The dark defective regions exhibit significant diffraction contrast due to the strains related to the
Conclusion
Our results indicate that the nitrogen implantation into silicon carbide results in the formation of the silicon carbonitride layer. The epitaxial overgrowth of the implanted SiCN layer results in high quality single crystal 4H-SiC layer. High resolution imaging of structural defects revealed the formation of Si3N4/Si2CN4 nanocrystalline inclusions and amorphous graphitic component in the implanted layer. XPS revealed significant change in the bonding structure and chemical states in the
Acknowledgements
The authors acknowledge the facilities, scientific and technical assistance of the Australian Microscopy and Microanalysis Research Facility at the Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, a facility funded by The University, State and Commonwealth Governments.
References (10)
- et al.
Diam. Relat. Mater.
(2007) - et al.
Nucl. Instr. and Meth. B
(2007) - et al.
Nucl. Instr. and Meth. B
(1992) - et al.
Nucl. Instr. and Meth. B
(1993) - et al.
Nucl. Instr. and Meth. B
(1997)
Cited by (6)
Characterization of crystalline SiCN formed during the nitridation of silicon and cornstarch powder compacts
2017, Journal of Alloys and CompoundsCitation Excerpt :Si-C-N system ceramics and their composites have great potential applications in the harsh environment or at high temperatures [7,8]. Si-C-N ceramics in the form of bulks, fibers, coatings and thin films were prepared by polymer derived ceramics (PDCs) route, ion implantation, physical vapor deposition (PVD) and chemical vapor deposition (CVD), respectively [9–13]. Moreover, most of Si-C-N ceramics fabricated by PDCs were amorphous, which had higher glass transformation point [14].
Structural and compositional complexity of nitrogen implantation in silicon carbide
2012, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and AtomsCitation Excerpt :Importantly, we have shown that the central layer is predominantly composed of Si3N4 and graphitic structure. This is inconsistent with initial work [5] done on α-SiC implanted by nitrogen at 1100 °C which reported that the implanted region was composed solely of SiCN, but is consistent with more recent XPS data [16]. However, given our new understanding of the substructure of the implanted layer, it is evident that the limited spatial resolution of the XPS technique would have meant that it would not have been possible to gain a true analysis of the implanted regions.
Amorphous boron containing silicon carbo-nitrides created by ion sputtering
2011, Surface and Coatings TechnologyCitation Excerpt :The presence of CC bonds and potentially Carbon nano-clusters is unexpected but there is evidence that even SiCN, synthesised by different methods, tends to have a significant number of CC bonds. In the experiment where SiCN was created by Nitrogen implantation into SiC [26] the XPS data, after a 1000 eV Ar etch, show the presence of graphitic Carbon. This could have been attributed to accumulation of Carbon on the surface due to preferential sputtering, but the authors also have done Electron Energy Loss Spectroscopy (EELS) experiments and demonstrated clustered sp2 bonded Carbon, which indicates preferential formation of Si–N at the expense of SiC bonds.
Wetting and interfacial behavior of molten Al–Si alloys on SiC monocrystal substrates: effects of Cu or Zn addition and Pd ion implantation
2018, Journal of Materials Science: Materials in ElectronicsTris(diethylamino)silane-A new precursor compound for obtaining layers of silicon carbonitride
2012, Glass Physics and ChemistryFrom organosilicon precursors to multifunctional silicon carbonitride
2012, Russian Journal of General Chemistry