Integration of CMOS process-compatible optoelectronic interconnects for high-speed communications

Abstract

The design and integration of a fully embedded Si-CMOS process-compatible optical interconnects are presented. The transmitting and receiving functions will be incorporated within the embedded optoelectronic interconnection layers of 3-D integrated multilayer boards and ASICs. All elements including waveguide, coupler, detector and laser for the fully embedded board-level optical interconnection system are developed. The propagation loss of waveguide is 0.58 dB/cm at 632.8 nm and 0.21 dB/cm at 850 nm. The 45-degree TIR (total internal reflection) micro-mirror couplers with high coupling efficiencies are formed by reactive ion etching. The MSM (metal-semiconductor-metal) photo-detector array is fabricated on a GaAs wafer by a CMOS compatible technique. The external quantum efficiency of 0.4 A/W and 3 dB bandwidth of the integrated MSM photo-detector of 2.648 GHz are experimentally confirmed. The VCSEL array with a sacrificial layer for the epitaxial liftoff of VCSEL from the GaAs substrate is designed and manufactured. A 1 X 12 array of VCSELs, MSM photo- detectors and polyimide channel waveguides via 45-degree TIR micro-couplers are integrated on Si wafer. The experimental performances of the highly integrated system are given.