7 September 2017 Germanium photodetectors fabricated on 300 mm silicon wafers for near-infrared focal plane arrays
Author Affiliations +
SiGe p-i-n photodetectors have been fabricated on 300 mm (12”) diameter silicon (Si) wafers utilizing high throughput, large-area complementary metal-oxide semiconductor (CMOS) technologies. These Ge photodetectors are designed to operate in room temperature environments without cooling, and thus have potential size and cost advantages over conventional cooled infrared detectors. The two-step fabrication process for the p-i-n photodetector devices, designed to minimize the formation of defects and threading dislocations, involves low temperature epitaxial growth of a thin p+ (boron) Ge seed/buffer layer, followed by higher temperature deposition of a thicker Ge intrinsic layer. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated uniform layer compositions with well defined layer interfaces and reduced dislocation density. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) was likewise employed to analyze the doping levels of the p+ and n+ layers. Current-voltage (I-V) measurements demonstrated that these SiGe photodetectors, when exposed to incident visible-NIR radiation, exhibited dark currents down below 1 μA and significant enhancement in photocurrent at -1 V. The zero-bias photocurrent was also relatively high, showing a minimal drop compared to that at -1 V bias.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
John W. Zeller, John W. Zeller, Caitlin Rouse, Caitlin Rouse, Harry Efstathiadis, Harry Efstathiadis, Nibir K. Dhar, Nibir K. Dhar, Priyalal Wijewarnasuriya, Priyalal Wijewarnasuriya, Ashok K. Sood, Ashok K. Sood, } "Germanium photodetectors fabricated on 300 mm silicon wafers for near-infrared focal plane arrays", Proc. SPIE 10404, Infrared Sensors, Devices, and Applications VII, 104040H (7 September 2017); doi: 10.1117/12.2277958; https://doi.org/10.1117/12.2277958

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