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Journal ArticleDOI

Composition and luminescence of Si and SiO 2 layers co-implanted with Ga and N ions

04 Apr 2017-International Journal of Nanotechnology (Inderscience Publishers (IEL))-Vol. 14, pp 637

AbstractWith the aim to establish the possibility of synthesis of GaN inclusions by co-implantation of Ga and N ions in silicon and SiO2 films on a silicon substrate, the chemical composition and photoluminescence of implanted layers have been investigated. It is observed that the heavy loss of implanted atoms occurs owing to the out-diffusion (Ga from Si, and Ga and N from SiO2) in the process of post-implantation annealing. Preliminary implantation of nitrogen to form silicon nitride or oxynitride layers is shown to reduce the degree of impurity losses. In the photoluminescence spectrum of both Si and SiO2 subjected to Ga and N co-implantation, the band at 530-550 nm is present, which can be related to 'defect' luminescence of GaN. more

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Abstract: Transmission electron-microscopy examination revealed the appearance of a hexagonal silicon (9R polytype) inclusions in the subsrface silicon layer upon ion implantation and subsequent heat treatment of the SiO2/Si structure. The formation of this hexagonal phase is stimulated by mechanical stresses arising in the heterophase system in the course of ion implantation.

6 citations

Journal ArticleDOI
01 Dec 2018

1 citations

Journal ArticleDOI
Abstract: The formation of GaN nanocrystals in SiO2/Si and SiNx/Si dielectric layers implanted with Ga + and N + ions, followed by annealing at 950 °C for 60–120 min in N2, has been studied by high resolution transmission electron microscopy (HRTEM), synchrotron radiation X-ray diffraction (XRD), X-ray absorption fine structure (XAFS) technique at the Ga K-edge, as well as by Rutherford Backscattering spectrometry (RBS), X-Ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS) and Scanning electron microscopy (SEM). The effect of the dielectric matrix, of the gas annealing environment (N2) and of the annealing time at 950 °C have been investigated. GaN nanocrystals implanted near the surface are observed in SiO2/Si only. The hexagonal wurtzite crystalline structure was confirmed by HRTEM, XRD and Raman spectroscopy. However, the synthesis process is multiphasic as elemental Ga0 nanoparticles at larger depths and Ga2O3 rods (~200–300 nm) on the surface were formed in addition to implanted h-GaN, as shown by TEM, XAFS, SEM, XPS and Raman spectroscopy. Moreover, Ga atoms are always remaining on some vacant Si sites in the SiO2 matrix. The local environment around Ga is quite different in the SiNx matrix, as seen by XAFS. This difference can be explained by the gallium and nitrogen diffusions which are much faster in the case of the SiO2 matrix, as shown by RBS profiles. Results are discussed in close comparison with existing literature.
Journal ArticleDOI
Abstract: Synthesis of nanoparticles in insulators attracts tremendous attention due to their unique electrical and optical properties. Here, the gallium (Ga) and gallium nitride (GaN) nanoclusters have been synthesized in the silicon nitride matrix by sequential ion implantation (gallium and nitrogen ions) followed by either furnace annealing (FA) or rapid thermal annealing (RTA). The presence of Ga and GaN nanoclusters has been confirmed by Fourier-transform infrared, Raman and X-ray photoelectron spectroscopy. Thereafter, the effect of RTA and FA on the conduction of charge carriers has been studied for the fabricated devices. It is found from the current–voltage measurements that the carrier transport is controlled by the space charge limited current conduction mechanism, and the observed values of parameter m (trap density and the distribution of localized state) for the FA and RTA devices are ~2 and ~4.1, respectively. This reveals that more defects are formed in the RTA device and that FA provides better performance than RTA from the viewpoint of opto- and nano-electronic applications.