HWCVD a-Si:H interlayer slope waveguide coupler for multilayer silicon photonics platform

We present interlayer slope waveguides, designed to guide light from one level to another in a multi-layer silicon photonics platform. The waveguide is fabricated from hydrogenated amorphous silicon (a-Si:H) film, deposited using hot-wire chemical vapor deposition (HWCVD) at a temperature of 230°C. The interlayer slope waveguide is comprises of a lower level input waveguide and an upper level output waveguide, connected by a waveguide on a slope, with vertical separation to isolate other crossing waveguides. Measured loss of 0.17 dB/slope was obtained for waveguide dimensions of 600 nm waveguide width (w) and 400 nm core thickness (h) at a wavelength of 1550 nm and for transverse electric (TE) mode polarization.