Low Dark Current and High Responsivity 1020nm InGaAs/GaAs Nano-Ridge Waveguide Photodetector Monolithically Integrated on a 300-mm Si Wafer

• Published in: Journal of lightwave technology Vol. 39; no. 16; pp. 5263 - 5269
• Main Authors: Ozdemir, Cenk Ibrahim, De Koninck, Yannick, Yudistira, Didit, Kuznetsova, Nadezda, Baryshnikova, Marina, Van Thourhout, Dries, Kunert, Bernardette, Pantouvaki, Marianna, Van Campenhout, Joris
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aspect ratio; CMOS; Dark current; Epitaxial growth; Gallium arsenide; III-V semiconductor materials; Indium gallium arsenides; Metallizing; monolithic integration; Multi Quantum Wells; nano-ridge engineering; optical simulation; Optical waveguides; Photodetectors; Photometers; Photonics; Plugs; quantum well devices; Quantum wells; semiconductor waveguides; Silicon; silicon photonics; Waveguides
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2021.3084324

We report on high-quality InGaAs/GaAs multi-quantum well waveguide photodetectors, monolithically integrated through metalorganic vapor-phase selective-area epitaxial growth and contact metallization in a 300-mm CMOS pilot line. The photodetectors are implemented using the nano-ridge engineering concept, leveraging aspect-ratio trapping in combination with precise control of the nano-ridge cross section dimensions and composition. The InGaAs/GaAs p-i-n nano-ridge photodetectors are shown to achieve high internal responsivities of up to 0.65 A/W at −1 V bias and 1020 nm wavelength. A clear correlation is observed between measured responsivity and contact-plug design, correlating well with simulation models. In addition, a record-low dark current density of 1.98 × 10 −8 A/cm 2 and low absolute dark currents of <1 pA are demonstrated, illustrating the high quality of the III-V materials and effective in-situ InGaP surface passivation layers. Initial RF measurements suggest RC-limited photodetection bandwidths in the GHz range. These results illustrate the strong potential of the III-V/Si nano-ridge epitaxy and waveguide device concept, to complement the Silicon Photonics toolbox with high-quality, high-throughput III-V functionality.