Design and Development of Si/SiGe Optical Source, Waveguide for On-Chip

A series of second generation of on-chip optical communication links of 50µm length, utilizing 650 ¿ 850 nm propagation wavelengths, have been designed and realized, with a SiGe radio frequency (RF) 0.35µm bipolar process. Micron dimensioned optical sources, silicon nitride waveguides and detectors were all integrated on the same chip to form a complete communication on-chip micro-optical links. Avalanche based Si LEDs (Si Av LEDs), Schottky contacting, TEOS densification strategies, silicon nitride based waveguides, and state of the art SiGe bipolar detector technologies were used as key design strategies. From the measurement, best performances of the designed on-chip optical links show optical edge-coupling from source to detector with -30dB total optical link budget loss up to 500MHz in cut off frequency. We observed that the good alignment of the waveguide with the source and the good efficiency of each integrated device are then clearly achieved. Higher frequency performances are also envisaged from preliminary measurements.