We demonstrate normal incidence p-i-n photodiodes on selective-area-grown Ge using multiple hydrogen annealing for heteroepitaxy for the purpose of monolithic integration. An enhanced efficiency in the near-infrared regime and the absorption edge shifting to longer wavelength is achieved due to 0.14% residual tensile strain in the selective-area-grown Ge. The responsivities at 1.48, 1.525, and 1.55 μ are 0.8, 0.7, and 0.64 A/W, respectively, without an optimal antireflection coating. These results are promising toward monolithically integrated on-chip optical links and in telecommunications.
Bibliographical noteFunding Information:
Manuscript received August 9, 2009. First published October 2, 2009; current version published October 23, 2009. This work was supported in part by FCRP Interconnect Focus Center. The review of this letter was arranged by Editor P. K.-L. Yu. H.-Y. Yu, S. Ren, W. S. Jung, D. A. B. Miller, and K. C. Saraswat are with the Department of Electrical Engineering, Stanford University, Stanford, CA 94305 USA (e-mail: firstname.lastname@example.org). A. K. Okyay is with the Department of Electrical Engineering, Bilkent University, Ankara TR-06800, Turkey. Color versions of one or more of the figures in this letter are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LED.2009.2030905 Fig. 1. (a) Schematic diagram of the cross section of normal incidence Ge/Si p-i-n photodiode. (b) Scanning electron micrograph of the circular mesas of the photodiodes. The circular p-i-n device has the ring-shaped contact with a ring width of 50 μm.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering