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Title: High bandwidth Ge p-i-n photodetector integrated on Si

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.2337003· OSTI ID:20883156
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  1. Institut fuer Halbleitertechnik, Universitaet Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)

The authors present a germanium on silicon p-i-n photodiode for vertical light incidence. For a Ge p-i-n photodetector with a radius of 5 {mu}m a 3 dB bandwidth of 25 GHz is measured at an incident wavelength of 1.55 {mu}m and zero external bias. For a modest reverse bias of 2 V, the 3 dB bandwidth increases to 39 GHz. The monolithically integrated devices are grown on Si with solid source molecular beam epitaxy. The complete detector structure consisting of a highly p-doped Ge buried layer, an intrinsic absorption region, and a highly n-doped top contact layer of Ge/Si is grown in one continuous epitaxial run. A low growth temperature sequence was needed to obtain abrupt doping transitions between the highly doped regions surrounding the intrinsic layer. A theoretical consideration of the 3 dB bandwidth of the Ge detector was used to optimize the layer structure. For a photodiode with 5 {mu}m mesa radius the maximum theoretical 3 dB frequency is 62 GHz with an intrinsic region thickness of 307 nm.

OSTI ID:
20883156
Journal Information:
Applied Physics Letters, Vol. 89, Issue 7; Other Information: DOI: 10.1063/1.2337003; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English