Open AccessAnalysis of stress distribution in microfabricated germanium with external stressors for enhancement of light emission
Author(s) -
Kazuki Tani,
Katsuya Oda,
T. Ido
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.413503
Subject(s) - materials science , germanium , ultimate tensile strength , strain (injury) , silicon , strain engineering , silicon nitride , substrate (aquarium) , stress (linguistics) , optics , perpendicular , optoelectronics , composite material , medicine , linguistics , oceanography , philosophy , physics , geometry , mathematics , geology
In the field of silicon photonics, germanium (Ge) is an attractive material for monolithic light sources. Tensile strain is a promising means for Ge based light sources due to enhancing direct band gap recombination. We investigated strain engineering in Ge using silicon nitride (SiN x ) stressors. We found that microfabricated Ge greatly improves the tensile strain because SiN x on the Ge sidewalls causes a large tensile strain in the direction perpendicular to the substrate. Tensile strain equivalent to an in-plane biaxial tensile strain of 0.8% at maximum was applied, and the PL emission intensity was improved more than five times at the maximum.