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We investigated the photoluminescence (PL) and electronic properties of both undoped and doped silicon carbonitride (SiCN) thin films, fabricated using electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD). The PL intensity of SiCN films is highly dependent on the annealing temperature and doping condition with rare-earth metals. Notably, Ce+3- and Tb+3-related luminescence were observed from doped samples after being annealed in nitrogen ambient at 1200degC for one hour. The electronic characteristics of these doped and un-doped films were analyzed using soft X-ray absorption near edge structure (XANES) and X-ray emission spectroscopy (XES) measurements, showing significant structural re-ordering occurs as the annealing temperatures were increased.

The formation of Si-nc embedded in amorphous Si oxides promoted by thermal annealing of SiyO1-y films (y=0.34-0.45) fabricated by plasma enhanced chemical vapor deposition is examined by X- ray diffraction and electron microscopy. UV and synchrotron radiation excited photoluminescence from the obtained structures is also studied and its origin elucidated

We investigate the thin film properties of the amorphous hydrogenated silicon carbonitride (a-SiCN:H) deposited by the electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD) technique. The elemental composition, film density, and complex refractive index of the SiCN films were analyzed as functions of hydrocarbon precursors’ (acetylene (C2H2) or methane (CH4)) flow rates. The difference in the reactivity and hydrogen content of the carbon precursors influence the thin film properties. The highest breakdown voltage obtained from our thin films was 29 V. Preliminary results of nanoindentation of the thin films are also presented in order to compare the hardness performance of the thin films obtained by different carbon sources.

Rapid thermal annealing has been used to study the changes in luminescence and structure from silicon-rich silicon nitride films for annealing times ranging from 2 seconds to 1 hour at 600 and 800°C. Silicon nanoclusters formed within the silicon nitride host matrix provided the source of the luminescence in the films through quantum confinement effects. Room temperature photoluminescence spectra exhibited a large, abrupt red-shift in emission after only 2 seconds of annealing, indicating early formation and growth of the silicon nanoclusters occurs through a fast transient diffusion mechanism. This initial shift was followed by a slower but steady growth of the nanoclusters as the annealing time was increased further. X-ray absorption near edge structure at the Si K- and L3,2-edges supported the trends observed in the photoluminescence spectra, providing evidence of silicon nanocluster growth and restructuring of the silicon nitride host matrix over the course of annealing.

Luminescent Si-based materials are of significant interest due to their potential applications in the fields of photonics and solid state lighting. The use of rare earth dopants incorporated into Si-based materials allows the attainment of specific wavelengths of emission for color tunability. Details of the RE luminescence and even the ability to obtain luminescence are strongly dependent on the composition and structure of the Si-based host material. Through the use of X-ray absorption spectroscopy details of the atomic bonding environment of the films has been obtained. X-ray excited optical luminescence, measured after excitation at the absorption edges of the constituent atoms within these materials, reveals that excitation of the rare earth ions occurs primarily at energies related to oxygen states.

Luminescent silicon nanoclusters have been formed in silicon-rich silicon nitride and silicon-rich silicon oxynitride films grown using inductively coupled plasma chemical vapour deposition. The luminescent properties and electronic structure of the films have been investigated through ultraviolet-excited photoluminescence and synchrotron-based X-ray absorption spectroscopy experiments at the Si K- and L3,2-edges, respectively. In the silicon-rich silicon nitride films, luminescence in the visible was observed from quantum confinement effects and inter-bandgap defect levels while X-ray absorption spectroscopy indicates a structural reordering of the silicon nanoclusters and nitride host matrix with increased silicon nanocluster phase separation, occurring at lower annealing temperatures in more silicon-rich films. Luminescence from the silicon-rich silicon oxynitride films appeared to be defect-related and only the silicon oxide and nitride host matrices exhibited structural reordering when annealed, while there was no change in the structure of the silicon nanoclusters.

Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effect that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different chemical vapour deposition (CVD) based systems: plasma-enhanced CVD (PECVD), inductively coupled plasma CVD (ICP CVD), and electron cyclotron resonance PECVD (ECR PECVD). Photoluminescence experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing, which primarily affected the emission intensity. X-ray absorption spectra at the Si K- and L3,2-edges exhibited composition dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions.

We have studied photoluminescence (PL) from SiO2 films co- doped with (Er, Ge) deposited by magnetron sputtering of an Er+Ge+SiO2 composite target in pure Ar ambient. Under excitation of a 325 nm He-Cd laser line, blue emission bands around 400 nm and near infrared bands around 800 nm have been observed, which are attributed to Ge-related defects and Ge nanoclusters (Ge-ncls), respectively. Strong Er3+ PL at 1.54 μm was also observed from the films, while the Er PL intensity of a control Er-doped SiO2 film (i.e., without Ge), is negligible under the same excitation. All the PL intensities vary as functions of thermal annealing temperatures. The results demonstrate that the significant enhancement of Er PL in the (Er, Ge) co-doped SiO2 films are due to the incorporation of Ge. The roles of Ge-ncls and Ge-related defects to the Er3+ excitation are discussed.

Si nanoclusters embedded in two different dielectric matrices, silicon oxide and silicon nitride, have been formed through annealing of Si-rich silicon oxide (SRSO) and Si-rich silicon nitride (SRSN) thin films. The light emitting properties of these materials have been analyzed through room temperature UV-excited photoluminescence (PL) experiments. Features of the PL spectra from both types are presented and the nature of light emission from Si-nanoclusters is discussed on the basis of the results from these two different host environments.