CMOS photonics

Light will be connecting CMOS chips sooner than you think. While every major semiconductor company is exploring silicon photonics in their research labs, Luxtera has implemented a practical version of the technology in a high-volume production CMOS process. The base process is Freescale´s 0.13 μm SOI CMOS, used to manufacture many of their high-performance PowerPC processors. In addition to the basic capabilities of the existing electronics process, Luxtera has augmented the process with the complete set of photonics functions required for enabling digital optical links between CMOS chips. Key elements of that capability include the ability to modulate, filter, switch and detect optical signals directly in the silicon. In effect, Luxtera has enlarged the available devices in the design library to include the complete set of optical functions required for advanced transceiver design. First, the basic description of the optical library components will be given, and the fundamental performance parameters required for systems design will be explained. Several styles of modulators operating >10 GHz with commercially competitive performance parameters will be shown, in addition to a robust waveguide coupling technology producing <2 dB insertion loss to deep submicron waveguides. Second, architectures for advanced high-bandwidth chip to chip interconnect will be presented, along with the scaling potential this technology has to enable terabit class optical interconnect between CMOS die.