Logo image
Back
Non-destructive characterization of silicon nanowires and nanowire coatings using mid-infrared spectroscopy
Journal article   Open access   Peer reviewed

Non-destructive characterization of silicon nanowires and nanowire coatings using mid-infrared spectroscopy

S. Maryam Vaghefi Esfidani, Daniel W. Keefe, Fatima Toor and Thomas G. Folland
Applied physics letters, Vol.124(19), 191603
05/06/2024
DOI: 10.1063/5.0191436
url
https://doi.org/10.1063/5.0191436View
Published (Version of record) Open Access

Related content

Cites

Abstract

Silicon nanowires (SiNWs) have attracted much attention owing to their potential applications in electronics and photonics, while remaining as a cost-effective material platform. Key material properties in engineering SiNWs for different applications include their length, density, and presence of oxides or other chemicals on the surface. However, monitoring these properties is challenging, as scanning electron microscopy and atomic force microscopy (AFM), which directly image the wires, require destructive cleaving of the sample. This paper uses polarized, variable-angle Fourier Transform IR reflectance spectroscopy as a nondestructive technique to characterize the areal density and length of metal-assisted chemically etched SiNW arrays. In addition to the ability to characterize “as-etched” wires, we show that IR spectroscopy can also measure few-nanometer thick layers of aluminum oxide (AlOx) grown radially around the length of the SiNWs utilizing atomic layer deposition. Despite sample inhomogeneities, an effective medium theory (EMT) model can determine the length and density of the NWs for a range of lengths between 3 and 14 μm. The EMT can also reproduce the experimentally measured vibrational bands for coated NWs, demonstrating that IR spectroscopy can also evaluate the presence of molecular contaminants on the wires.

Details

Metrics

114 Record Views
Logo image