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Abstract:We demonstrate a 67 GHz bandwidth silicon-contacted germanium waveguide p-i-n photodetector operating at -1 V with 6.8 fF capacitance. The dark current is below 4 nA. The responsivity is 0.74 A/W at 1550 nm and 0.93 A/W at 1310 nm wavelength. 56 Gbps on-off-keying data reception is demonstrated with clear open eye diagrams in both the Cband and O-band.

Silicon photonics integrated circuits are considered to enable future computing systems with optical input-outputs co-packaged with CMOS chips to circumvent the limitations of electrical interfaces. In this paper we present the recent progress made to enable dense multiplexing by exploiting the integration advantage of silicon photonics integrated circuits. We also discuss the manufacturability of such circuits, a key factor for a wide adoption of this technology.

We report on measurements of the time dependent capacitance of a RF MEMS shunt switch. A high time resolution detection setup is used to determine switching time and motion of the device. From the equation of motion the damping force is extracted. The measured damping force is found to be approximately proportional to the speed over the gap distance to the third power (F D ∝ v/z 3 ), in good agreement with squeeze film damping theory. Measurements at low pressure show underdamped harmonic oscillations in the opening motion and contact bounce effects in the closing motion. Effects of dielectric charging on the C-V curves are discussed. Experimental results are compared with electromechanical and damping simulations.

Abstract-We demonstrate 100-Gbps silicon-contacted germanium waveguide p-i-n photodetectors integrated on imec's silicon photonics platform. The performance of 14 and 20 µm long devices is compared. The responsivity of the devices is 0.74 and 0.92 A/W at 1550 nm, respectively.

We present a dark current analysis in waveguide-coupled germanium vertical p-i-n photodetectors. In the analysis, surface leakage current and bulk leakage current were separated, and their activation energies were extracted. Surface leakage current originating from the minority carrier generation on the Ge layer sidewalls, governed by the Shockley-Read-Hall process and enhanced by the trap-assisted-tunneling process, was identified as the main contribution to the dark current of vertical p-i-n photodiodes at room temperature. The behavior of this surface leakage current as a function of temperature and (reverse bias) voltage is well reproduced by using the Hurckx model for trap-assisted-tunneling.

Abstract-We report a high-performance germanium waveguide photodetectors (WPDs) without doping in germanium or direct metal contacts on germanium, grown on and contacted through a silicon p-i-n diode structure. Wafer-scale measurements demonstrate high responsivities larger than 1.0 A/W across the C-band and low dark current of ∼3 nA at -1 V and ∼8 nA at -2 V. Owing to its small dimensions, the Ge WPD exhibits a high optoelectrical 3-dB bandwidth of 20 and 27 GHz at low-bias voltages of -1 and -2 V, respectively, which are sufficient for operation at 28 Gb/s. The reduced processing complexity at the tungsten contact plug module combined with the high responsivity makes these Ge WPD devices particularly attractive for emerging low-cost CMOS-Si photonics transceivers Index Terms-Germanium photodetector, optical interconnects, silicon photonics.

Silicon photonics has become in the past years an important technology adopted by a growing number of industrial players to develop their next generation optical transceivers. However most of the technology platforms established in CMOS fabrication lines are kept captive or open to only a restricted number of customers. In order to make silicon photonics accessible to a large number of players several initiatives exist around the world to develop open platforms. In this paper we will present imec's silicon photonics active platform accessible through multi-project wafer runs