3D multiphysics transient modeling of vertical Ge-on-Si pin waveguide photodetectors

We report transient simulations of Ge-on-Si vertical pin waveguide photodetectors (WPDs), where the optical generation term used by the time-domain model is the FDTD solution of the electromagnetic problem treated as a spatially-distributed pulsed signal. This approach, validated against experimental measurements of the frequency response, paves the way to future studies of the dynamic response of WPDs, enabling the description of complex modulation schemes including saturation effects and current tails due to slow carriers

Modeling the frequency response of vertical and lateral Ge-on-Si waveguide photodetectors: Is 3D simulation unavoidable?

Using a 3D multiphysics model as a reference, we investigate the achievements and limitations of a simpler 2D drift-diffusion model to reproduce and optimize the electrooptical frequency response of vertical and lateral Ge-on-Si waveguide photodetectors

Guided-wave near-infrared detector in polycrystalline Germanium on Silicon”, Appl. Phys. Lett. 87, 203507 (2005)

Using a guided wave configuration, we demonstrate a novel polyGe-on-Si heterostructure photodetector realized on a silicon-on-insulator by a low deposition temperature process. Without further detector optimization, at 1.55 µm we measured wall-plug responsivities as high as 15 mA/W with an effective responsivity in excess of 300 mA/W. Device operation was demonstrated up to 2.5 Gbit/

Ge-On-Si Approaches To The Detection Of Near-Infrared Light

We review our recent results on Ge-based near-infrared photodetectors grown on silicon. We fabricated metal-semiconductor-metal photodetectors based on epitaxial pure-Ge grown on silicon by Chemical Vapor Deposition. Material characterization and device performances are illustrated and discussed. Exploiting a novel approach based on evaporation of polycrystalline-Ge on silicon, we also realized efficient near-infrared photodiodes with good speed and sensitivity. Finally, multiple-element devices were designed, fabricated, and tested, such as a voltage-tunable wavelength-selective photodetector based on a SiGe superlattice and a linear array of 16 photodetectors in poly-Ge on Si

High-Speed Near Infrared Optical Receivers Based on Ge Waveguide Photodetectors Integrated in a CMOS Process

We discuss our approach to monolithic intergration of Ge photodectors with CMOS electronics for high-speed optical transceivers. Receivers based on Ge waveguide photodetectors achieve a sensitivity of −14.2 dBm (10−12 bit error rate (BER)) at 10 Gbps and 1550 nm

Array di fotorivelatori per il vicino infrarosso in germanio policristallino integrato con elettronica CMOS

We report recent results on innovative poly-Ge on silicon photodetectors monolithically integrated onto silicon CMOS electronics. We demonstrate the operation of linear and two dimensional arrays of near infrared photodetectors

Polycrystalline germanium enables NIR photodetectors integrated with silicon CMOS electronics

In the past two decades SiGe has been the material of choice for the realization of near infrared (NIR: 0.7-2ƒÝm) optoelectronic devices based on silicon and its technology, and several groups have developed high performance NIR photodetectors fabricated on Si substrates [ ]. Nevertheless, the existing gap between a good device and its monolithic integration with VLSI electronics on silicon had not been filled until recently, when we demonstrated the first silicon integrated circuit (IC) capable of NIR detection. [2] This was fabricated using a standard technology, but adopting a low temperature approach towards polycrystalline Ge deposition. A low thermal budget, in fact, allows monolithic integration of poly-Ge/Si heterojunction photodiodes with VLSI silicon electronics as a back-end process. After an introduction on both silicon-based NIR photodetectors and compatibility issues, we describe the novel poly-Ge deposition process and discuss the performance of poly-Ge_on_Si devices. Finally, we illustrate linear arrays of NIR detectors integrated with silicon CMOS electronics (front-end, addressing, A/D conversion and readout), demonstrating their operation and the full compatibility with standard Si CMOS technology

NIRCAM2: a CMOS integrated circuit in polycrystalline germanium for near infrared imaging

we describe the NIRCAM2, i.e. the first two-dimensional array of 64x8 pixels equipped with readout electronics. The chip includes 64 analog to digital converters, dark current cancellation circuitry and test/calibration facilities. We report on its fabrication, electronic as well as optoelectronic characterization, operation as a CMOS near infrared image sensor

Monolithic and hybrid near infrared detection and imaging based on poli-Ge photodiode arrays”, Optic. Mater. 27, 1079-83 (2005)

In recent years, several Ge-on-Si technologies for the fabrication of near infrared photodetectors on Si substrates were proposed. In particular, using a low temperature (300 °C) technique, we have demonstrated poly-Ge_on_Si detectors with high speed and good NIR responsivity. The low process temperature allows the monolithic integration of the detectors as a final step in the fabrication of Si CMOS integrated circuits. After an introduction on poly-Ge, we describe a novel integrated chip (NIRCAM-1) designed as a readout/control circuit for arrays of 64 (32) poly-Ge_on_Si photodetectors. The photodiodes, monolithically integrated (wirebonded with a hybrid approach) on the IC, generate a photocurrent which is then ADC converted after subtraction of the dark component, thus allowing a convenient digital readout of the array. The extensive optoelectronic characterization of the IC is presente