| Silicon-based photonics requires several components, such as a light source, an amplifier/waveguide to transfer the signal, and a photodetector to detect the signal. The motivation for using these silicon-based technologies in photonics applications is two-fold: economic advantages offered by the compatibility with mature silicon IC manufacturing and its excellent material properties for photonic devices (high thermal conductivity, high optical damage threshold, etc.). One of the major challenges in the realization of this technology is the Si-based light source. Because of its indirect bandgap, silicon has very inefficient band-to-band radiative electron-hole recombination. To overcome this obstacle, tremendous research efforts have been focused on finding methods to enhance light emission from silicon compatible materials such as nanocrystals, Si/SiO2 superlattices, erbium-doped silicon-rich oxides, erbium oxides/silicates, and SiO2/Si MOS structures. This thesis research work will focus on the last three mentioned methods to enhance light emission.;Room temperature photoluminescence (PL) at the standard telecommunication wavelength of 1540 nm has been achieved from erbium-doped amorphous silicon oxycarbide (a-SiCxOy). The first phase of this thesis work will utilize the optimized a-SiC0.5O1.0 matrix in an erbium-doped silicon-based MOS structure [Al/a-SiC 0.5O1.0:Er/p-Si] as the active layer (emitter). In addition, the effect of adding a SiO2 interlayer to the MOS structure [Al/a-SiC 0.5O1.0:Er/SiO2/p-Si] will be discussed. The second phase will enhance the device stack by replacing the active layer with an erbium-based film (erbium oxide/silicate), thereby increasing the concentration of available light emitting centers in the emitter region. In the third phase, the device stack will be further optimized by investigating the role of hydrogen passivations on the defect density of the film stack. In particular, hydrogen passivations will be performed on [Al/SiO2/p-Si] devices. The final phase will utilize the knowledge gleaned from the prior phases in order to create a device stack with enhanced luminescence properties based on material processing and characterization of an optimized erbium-based MOS structure on SiO2/Si. |
