40 research outputs found
Extending the emission wavelength of Ge nanopillars to 2.25 μm using silicon nitride stressors
The room temperature photoluminescence from Ge nanopillars
has been extended from 1.6 μm to above 2.25 μm wavelength through
the application of tensile stress from silicon nitride stressors deposited by
inductively-coupled-plasma plasma-enhanced chemical-vapour-deposition.
Photoluminescence measurements demonstrate biaxial equivalent tensile
strains of up to ~ 1.35% in square topped nanopillars with side lengths of
200 nm. Biaxial equivalent strains of 0.9% are observed in 300 nm square
top pillars, confirmed by confocal Raman spectroscopy. Finite element
modelling demonstrates that an all-around stressor layer is preferable to a
top only stressor, as it increases the hydrostatic component of the strain,
leading to an increased shift in the band-edge and improved uniformity over
top-surface only stressors layers
Expanding the Ge emission wavelength to 2.25 μm with SixNy strain engineering
Photoluminescence up to 2.25 μm wavelength is demonstrated from Ge nanopillars strained by silicon nitride
stressor layers. Tensile biaxial equivalent strains of up to ~1.35% and ~0.9% are shown from 200 × 200 nm, and
300 × 300 nm square top Ge pillars respectively. Strain in the latter is confirmed by Raman spectroscopy, and
supported by finite element modelling, which gives an insight into the strain distribution and its effect on the
band structure, in pillar structures fully coated by silicon nitride stressor layers