The Comparative Investigations of Structural and Optical Properties of GaSb nanocrystals / Si layers

Optical and structural properties of GaSb nanocrystals fabricated by co-implantation of Ga and Sb ions in single crystalline Si (100), followed by thermal treatment are investigated. In the first group of samples named Si / GaSb the implantation of Ga ions was followed by Sb implantation, whereas in the second group of samples named Si / SbGa with increased by factor 1.4 ion fluence the order of implantation was inverted. The presence of nanocrystals in both kinds of samples was proved by TEM and RS experiments. Low-temperature PL measurements show a PL broad band in the region at 0.75-1.1 eV for Si / SbGa samples annealed at 900 °C. No PL was observed in the Si/SbGa samples after annealing at 1100 °C. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

Effects of annealing regims on the structural and optical properties of inas and gasb nanocryctals created by ion-beam synthesis in Si matrix

We have studied the ion-beam synthesis of InAs and GaSb nanocrystals in Si by high-fluence implantation of (As+In) and (Ga+Sb) ions followed a thermal annealing. In order to characterize the implanted samples Rutherford backscattering spectrometry in combination with the channelling (RBS/C), transmission electron microscopy (TEM), Raman spectrometry (RS) and low-temperature photoluminescence (PL) techniques were employed. It was demonstrated that by introducing getter, varying the ion implantation temperature, ion fluences and post-implantation annealing duration and temperature it is possible to form InAs and GaSb nanocrystals in the range of sizes of (2 – 80) nm and create different types of secondary defects distribution. RS results confirm the crystalline state of the clusters in the silicon matrix after high-fluence implantation of heavy (As+In) and (Ga+Sb) ions. Significant redistribution of implanted species has been revealed after “hot” implantation and post-implantation annealing. We have suggested that it is caused by non-equilibrium diffusion. A broad band in the spectral region of 0.7 – 1.1 eV is detected in the photoluminescence spectra of the samples. The nature of this PL band is discussed.We have studied the ion-beam synthesis of InAs and GaSb nanocrystals in Si by high-fluence implantation of (As+In) and (Ga+Sb) ions followed a thermal annealing. In order to characterize the implanted samples Rutherford backscattering spectrometry in combination with the channelling (RBS/C), transmission electron microscopy (TEM), Raman spectrometry (RS) and low-temperature photoluminescence (PL) techniques were employed. It was demonstrated that by introducing getter, varying the ion implantation temperature, ion fluences and post-implantation annealing duration and temperature it is possible to form InAs and GaSb nanocrystals in the range of sizes of (2 – 80) nm and create different types of secondary defects distribution. RS results confirm the crystalline state of the clusters in the silicon matrix after high-fluence implantation of heavy (As+In) and (Ga+Sb) ions. Significant redistribution of implanted species has been revealed after “hot” implantation and post-implantation annealing. We have suggested that it is caused by non-equilibrium diffusion. A broad band in the spectral region of 0.7 – 1.1 eV is detected in the photoluminescence spectra of the samples. The nature of this PL band is discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2083

Strong Room-Temperature Photoluminescence of Si-rich and N-rich Silicon-Nitride Films

Si-rich and N-rich silicon nitride films were deposited at low temperature 300 °C by using plasmaenhanced chemical vapor deposition (PECVD). The optical and structural properties of these films have been investigated by ellipsometry, Rutherford backscattering (RBS), transmission electron microscopy (TEM), Raman spectroscopy (RS) and photoluminescence (PL). The formation of silicon clusters in both Sirich and N-rich silicon nitride films after annealing at 900 °C and 1000 °C for hour in N2 ambient has been shown by TEM. Dependency of PL spectra on stoichiometry and post-annealing temperature was analyzed. The contribution of Si and N-related defects in emitting properties of Si-rich and N-rich SiNx has been discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

Phase Transformation in the Annealed Si-Rich SiNx Films Studied by Raman Scattering

The Si-rich SiNx films were deposited on Si wafers by low pressure chemical vapor deposition (LPCVD) technique followed by annealing at (800 – 1200) °C. Excess (overstoichiometric) Si content in nitride films was calculated from Rutherford backscattering data (RBS). Existence and evolution of Si nanoclusters from amorphous to crystalline ones under high temperature treatment were confirmed by Raman scattering (RS) measurements. Amorphous Si clusters have already existed in as-deposited SiNx films. Thermal treatment results in the formation of additional amorphous nanoclusters and in their crystallization with anneal temperature increasing. Nitride films annealed at 1200 °C contain crystalline Si clusters only. It was revealed a dependence of Si wafer’s Raman scattering intensity on the temperature of SiNx/Si structures annealing. This information in combination with RBS data has allowed us to estimate and distinguish the excess silicon aggregated in clusters and the excess silicon distributed over the silicon nitride matrix