Silicon nanowires and their characterization in the process of metal-assisted chemical etching of c-Si using spectroscopic ellipsometry

In this work, the preparation of c-Si nanowires was investigated using a two-stage metal-assisted chemical etching process. For characterization of structures at all stages of the process, spectroscopic ellipsometry was used and two approaches were used: a) determining and analysing the complex pseudo-dielectric function epsilon and b) determining parameters of simulated multilayer structures using the effective medium approximation. Taking into account the structure parameters measured from SEM images the spectra of psi and Delta were calculated and fitted to the experimental ones to obtain best convergence. The study of metal-assisted chemical etching process the Si process is intended for the development of silicon technology for obtaining structures of various topology (morphology) with functional components and creating on their basis sensory elements for bio and chemical reagents, taking into account the possibility of integration with micro and nanodevices on the chip.