Stress-Dependent Optical Extinction in LPCVD Silicon Nitride Measured by Nanomechanical Photothermal Sensing

Fuente: arXiv
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Main Authors: Kanellopulos, Kostas, West, Robert G., Emminger, Stefan, Martini, Paolo, Sauer, Markus, Foelske, Annette, Schmid, Silvan
Format: Preprint
Published: 2024
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author Kanellopulos, Kostas
West, Robert G.
Emminger, Stefan
Martini, Paolo
Sauer, Markus
Foelske, Annette
Schmid, Silvan
author_facet Kanellopulos, Kostas
West, Robert G.
Emminger, Stefan
Martini, Paolo
Sauer, Markus
Foelske, Annette
Schmid, Silvan
contents Understanding optical absorption in silicon nitride is crucial for cutting-edge technologies like photonic integrated circuits, nanomechanical photothermal infrared sensing and spectroscopy, and cavity optomechanics. Yet, the origin of its strong dependence on film deposition and fabrication process is not fully understood. This Letter leverages nanomechanical photothermal sensing to investigate optical extinction $κ_{\mathrm{ext}}$ at 632.8 nm wavelength in LPCVD SiN strings across a wide range of deposition-related tensile stresses ($200-850$ MPa). Measurements reveal a reduction in $κ_{\mathrm{ext}}$ from 10$^3$ to 10$^1$ ppm with increasing stress, correlated to variations in Si/N content ratio. Within the band-fluctuations framework, this trend indicates an increase of the energy bandgap with the stress, ultimately reducing absorption. Overall, this study showcases the power and simplicity of nanomechanical photothermal sensing for low absorption measurements, offering a sensitive, scattering-free platform for material analysis in nanophotonics and nanomechanics.
format Preprint
id arxiv_https___arxiv_org_abs_2406_14222
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Stress-Dependent Optical Extinction in LPCVD Silicon Nitride Measured by Nanomechanical Photothermal Sensing
Kanellopulos, Kostas
West, Robert G.
Emminger, Stefan
Martini, Paolo
Sauer, Markus
Foelske, Annette
Schmid, Silvan
Optics
Mesoscale and Nanoscale Physics
Materials Science
Applied Physics
Understanding optical absorption in silicon nitride is crucial for cutting-edge technologies like photonic integrated circuits, nanomechanical photothermal infrared sensing and spectroscopy, and cavity optomechanics. Yet, the origin of its strong dependence on film deposition and fabrication process is not fully understood. This Letter leverages nanomechanical photothermal sensing to investigate optical extinction $κ_{\mathrm{ext}}$ at 632.8 nm wavelength in LPCVD SiN strings across a wide range of deposition-related tensile stresses ($200-850$ MPa). Measurements reveal a reduction in $κ_{\mathrm{ext}}$ from 10$^3$ to 10$^1$ ppm with increasing stress, correlated to variations in Si/N content ratio. Within the band-fluctuations framework, this trend indicates an increase of the energy bandgap with the stress, ultimately reducing absorption. Overall, this study showcases the power and simplicity of nanomechanical photothermal sensing for low absorption measurements, offering a sensitive, scattering-free platform for material analysis in nanophotonics and nanomechanics.
title Stress-Dependent Optical Extinction in LPCVD Silicon Nitride Measured by Nanomechanical Photothermal Sensing
topic Optics
Mesoscale and Nanoscale Physics
Materials Science
Applied Physics
url https://arxiv.org/abs/2406.14222