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

Silicon nanowires (SiNWs) have attracted much attention and are highly promising for electronics and photonics applications, offering a cost-effective material platform. Monitoring material properties such as their length, density, and presence of oxides or other chemicals on the surface using imaging techniques is not ideal as they require destructive cleaving of the sample. This work aims to predict the density of SiNWs, a crucial factor influencing their performance, by employing variable angle Fourier Transform IR (FTIR) reflectance spectroscopy as a non-destructive technique. By knowing the length of the nanowire and the space between fringes, we can predict the density of metal-assisted chemically etched (MACE) SiNW arrays using Effective Medium Theory(EMT). This technique is also able to measure few-nanometer-thick layers of aluminum oxide (AlOx) grown radially around the SiNWs’ length using atomic layer deposition (ALD). We determine both length and density of the NWs for a range of NW lengths between 3 μm and 14 μm and we find that the best fit for SiNWs' areal fill fraction is 0.3 for our samples and processes.