Fabrication of silicon nanowires (SiNWs) with nanosphere lithography: a comparison approach with laser ablation

Abstract

The fabrication of Silicon nanostructures is still a point of interest to sustain a cheaper, faster, and more effective method. This work represents a comparison approach for the fabrication of SiNWs via modified Nanosphere lithography using polystyrene nanospheres (PS-NS) as templates against the Laser Ablation method. First, the Si type-p (111) wafer was treated with Oxygen/Argon Plasma to switch the wafer to the hydrophilic state to acquire an adequate nondispersive layer of PS-NS. The PS-NS was then dispersed in ethanol with a ratio [1:1]. The monolayer deposition on the wafer was achieved via 3-steps spinning with different rpm. The sizes of the PS-NS were then controlled by dry etching, using deep reactive ion etching (DRIE) for different periods to guide the size of the SiNWs. A silver (Ag) layer was then deposited on the structure to guide the silicon etching process via metal-assisted chemical etching (MACE) to control the length of the fabricated SiNWs. Another approach was to implement metal-assisted plasma etching (MAPE) first a layer of gold (Au) was sputtered on the sample using DC-Sputtering. The surface morphology of the structure has been investigated via field effect scanning electron microscopy (FE-SEM) and atomic force microscopy, while the optical characteristics were investigated via Fourier-transform infrared spectroscopy (FTIR) and photoluminescence (PL)