Systems and devices in a 30 GHz Silicon-on-Insulator platform

We present a 30 GHz silicon photonic platform that includes low-loss passive components, high-speed modulators and Ge-on-Si photodetectors. The platform is available to the community as part of the OpSIS-IME multi-project-wafer foundry service. We conclude with a proposal for a fully CMOS-compatible optical isolator based on multistage phase modulation. Introduction About five years ago the semiconductor industry arrived close to the fundamental limits in the scaling down of transistors, mainly due to issue of power dissipation. To continue the exponential scaling up of computing capabilities requires the development of massively parallel architectures, for which optical interconnects are widely recognized as an essential enabling technology. At a higher level, the demand for increased communication bandwidth in large data centers has continued through the past decades, driven by the rise of the Internet. However, the relative expense of discrete optical components used in standard communication links is a challenge for continued bandwidth scaling. Moreover, for on-chip interconnects, seamless integration next to the central processing units is a must. One proposed solution for the two above challenges that has gained attention in recent years is to build integrated photonic circuits on a silicon platform. Leveraging the investments made in complementary metal-oxide-semiconductor (CMOS) fabrication, it is possible to build lowcost, high-complexity systems in silicon that achieve close integration between electronics and photonics. Recent efforts have shown that such platforms can achieve impressive performance with the promise of very low costs and high yield. Luxtera has developed a 25 Gb/s platform, the first one that is fully integrated with CMOS. Kim et al. have demonstrated both modulators and detectors working at speeds of 30 Gb/s. Just recently, IMEC announced the upcoming launch of a fully integrated 25 Gb/s platform via the ePIXfab MPW. In this paper, we present the performance of the OpSIS-IME silicon photonics platform. This platform features a host of optimized passive elements such as low-loss grating couplers and waveguides, as well as high-speed active elements including 58 GHz gain-peaked Ge photodetectors, 45 GHz, high-tunability silicon ring modulators and 30 GHz traveling wave Mach-Zehnder modulators. The high bandwidth of the modulators and photodetectors enable the platform to support a data rate of 50 Gb/s per channel and potentially higher. The platform is available to the research community and to private developers as part of the OpSIS-IME multi-project-wafer (MPW) foundry service. Fabrication The silicon photonic circuits were fabricated at the Institute of Microelectronics (IME), a research institute of the Agency for Science, Technology and Research (A*STAR). SiliconFig. 1: Schematics of the layers cross-section Mo.3.B.2.pdf