Plasma Deposited Photo-Oxidated Organosilicon Polymer to Produce Etch-Free, On-Chip, Low Loss, High Density, Optical Waveguides

Research indicates that optical losses with current waveguides are several times worse than fiber optical cables. Development of an on chip waveguide is hampered by evidence that etch generated sidewall damage causes interface scattering and is a major factor in reduced signal propogation. On-chip waveguides must integrate with a variety of device types and process conditions. For example, gallium arsenide based opto-electronic devices are sensitive to heat and plasma or dry etching. When process and device issues, such as building coupling structures, are viewed together, it is evident that the major hurtles to optical interconnect are practical process/material integration issues. Ionic Systems has over five years experience with room temperature plasma deposited low cost, organosilicon photo-oxidated compounds. We propose to take advantage of the index of refraction changes in the exposed and unexposed material to fabricate on-chip waveguides with no subsequent etching. This method of on-chip optical fabrication provides potential elimination of multiple deposition and patterning steps, and the waveguide thus generated will have excellent optical boundaries eliminating or drastically reducing losses during optical propagation. The terms high performance, low loss, and etch free are inseparable for this process. The variable index of refraction makes a new class of optical devices possible for integration of optical components such as prisms or gratings in the beam waveguide itself.