Integrated Nanophotonic Silicon Devices For Next Generation Computing Chips

Development of the computing platform of the future depends largely on high bandwidth interconnects at intra-die level. Silicon photonics, as an innately CMOS compatible technology, is a promising candidate for delivering terabit per second bandwidths through the use of wavelength division multiplex (WDM) signaling. Silicon photonic interconnects offer unmatched bandwidth, density, energy efficiency, latency and reach, compared with the electrical interconnects. WDM silicon photonic links are viewed today as a promising solution for resolving the inter/intra-chip communication bottlenecks for high performance computing systems. Towards its maturity, silicon photonic technology has to resolve the issues of waveguide propagation loss, density of device integration, thermal stability of resonant devices, heterogeneous integration of various materials and many other problems. This dissertation describes the development of integrated photonic technology on silicon and silicon nitride platforms in the increased order of device complexity, from the fabrication process of low loss waveguides and efficient off-chip coupling devices, to the die-size reconfigurable lattice filters for optical signal processing. Particular emphasis of the dissertation is on the demonstration of CMOS-compatible, athermal silicon ring modulators that potentially hold the key to solving the thermal problem of silicon photonic devices. The development of high quality amorphous titanium dioxide films with negative thermo-optic coefficient enabled the fabrication of gigahertz-bandwidth silicon ring modulators that can be made insensitive to ambient temperature changes.