High speed and high responsivity germanium photodetector integrated in a Silicon-On-Insulator microwaveguide (original) (raw)
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42 GHz pin Germanium photodetector integrated in a silicon-on-insulator waveguide
Optics Express, 2009
A compact pin Ge photodetector is integrated in submicron SOI rib waveguide. The detector length is reduced down to 15 µm using butt coupling configuration which is sufficient to totally absorb light at the wavelength of 1.55 µm. A -3 dB bandwidth of 42 GHz has been measured at a 4V reverse bias with a responsivity as high as 1 A/W at the wavelength of 1.55 µm and a low dark current density of 60 mA/cm². At a wavelength of 1.52 µm, a responsivity of 1 A/W is obtained under -0.5 V bias. The process is fully compatible with CMOS technology.
Ge photodetectors integrated in Si waveguides
Silicon Photonics III, 2008
This paper reports theoretical and experimental investigations of germanium photodetectors integrated in silicon on insulator waveguides for metal-semiconductor-metal (MSM) photodetectors integrated in a slightly etched rib waveguide. Experimental characteristics of germanium on silicon photodetectors have been obtained using time measurements with femtosecond pulses and opto-RF experiments. For MSM structure with 1µm electrode spacing, the measured bandwidth under 6V bias is 25 GHz at 1.55 µm wavelength with a responsivity as high as 1 A/W and the bandwidth reaches 30GHz for 0.7µm electrode spacing under 1V bias.
CMOS-integrated high-speed MSM germanium waveguide photodetector
Optics Express, 2010
A compact waveguide-integrated Germanium-on-insulator (GOI) photodetector with 10 ± 2fF capacitance and operating at 40Gbps is demonstrated. Monolithic integration of thin single-crystalline Ge into frontend CMOS stack was achieved by rapid melt growth during source-drain implant activation anneal.
High Power Silicon-Germanium Photodiodes for Microwave Photonic Applications
2010
We demonstrate high current operation of an evanescently coupled Ge waveguide n-i-p photodetector grown on top of a Si rib waveguide. A 7.4 m 500 m device was found to dissipate 1.003 W of power (125.49 mA at 8 V). 2-D thermal simulations of the device show that the relatively high thermal conductivities of the intrinsic Ge region and the p + doped Si layer result in efficient heat transfer and hence, lower absorber temperatures when compared to a similar InP based waveguide photodiode. Additionally, to determine the feasibility of these devices for analog photonic applications, we performed large signal and small signal radio frequency (RF) measurements as well as linearity measurements. At 1 GHz and 40 mA of photocurrent, a third order output intercept point (OIP3) of 36.49 dBm is measured. The maximum RF power extracted at 1 GHz is 14.17 dBm at 60 mA of photocurrent and 7 V reverse bias.
IEEE Photonics Technology Letters, 2000
We report the demonstration of waveguided germanium-on-silicon-on-insulator metal-semiconductor-metal (MSM) photodetectors with novel silicon-carbon (Si : C) Schottky barrier enhancement layer. Significant suppression of dark current (I dark ) by 4 orders of magnitude was achieved over a conventional MSM photodetector due to an enhanced hole Schottky barrier height of 0.52 eV. At an applied bias V A of 1.0 V, a 03-dB bandwidth of 12 GHz at an incident wavelength of 1550 nm was demonstrated. Optical measurements performed at photon wavelengths of 1520-1570 nm reveal a uniform spectral response and quantum efficiency of 760 mA/W and 60%, respectively, demonstrating an effective photodetection for the entire C-band spectrum range.
Zero-bias 40Gbit/s germanium waveguide photodetector on silicon
Optics Express, 2012
We report on lateral pin germanium photodetectors selectively grown at the end of silicon waveguides. A very high optical bandwidth, estimated up to 120GHz, was evidenced in 10 µm long Ge photodetectors using three kinds of experimental setups. In addition, a responsivity of 0.8 A/W at 1550 nm was measured. An open eye diagrams at 40Gb/s were demonstrated under zero-bias at a wavelength of 1.55 µm.
Germanium on double-SOI photodetectors for 1550-nm operation
Semiconductor Photodetectors, 2004
We have fabricated and characterized the first resonant cavity enhanced (RCE) germanium photodetectors on double silicon-on-insulator substrates (Ge/DSOI) for operation around the 1550 nm communication wavelength. The Ge layer is grown through a novel two-step UHV/CVD process, while the underlying double-SOI substrate is formed through an ion-cut process. Absorption measurements of an undoped Ge-on-Si (Ge/Si) structure reveal a red-shift of the Ge absorption edge in the NIR, due primarily to a strain-induced bandgap narrowing within the Ge film. By using the strained-Ge absorption coefficients extracted from the absorption measurements, in conjunction with the known properties of the DSOI substrate, we were able to design strained-Ge/DSOI photodetectors optimized for 1550 nm operation. We predict a quantum efficiency of 76% at 1550 nm for a Ge layer thickness of only 860 nm as a result of both strain-induced and resonant cavity enhancement, compared to 2.3% for the same unstrained Ge thickness in a single-pass configuration. We also estimate a transit-time limited bandwidth of 28 GHz. Although the fabricated Ge/DSOI photodetectors were not optimized for 1550 nm operation, we were able to demonstrate an over four-fold improvement in the quantum efficiency, compared to its single-pass counterpart.
Ge-on-Si waveguide photodetectors: multiphysics modeling and experimental validation
2021 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD), 2021
This work compares a multiphysics modeling approach with experimental measurements of two Ge-on-Si butt-coupled waveguide photodetectors. The coupled threedimensional electromagnetic and electrical simulation of the frequency response shows promising agreement with the measurements at 1310 nm, and provides detailed information about significant microscopic quantities, such as the spatial distribution of the optical generation rate.