Victor H. Velez

Investigation on the reflectance properties on silicon nanowires grown by electroless etching

In this study, silicon nanowires (SiNWs) were fabricated at four different lengths of time and three etching solution concentrations at room temperature using the electroless etching technique in a silver nitrate (AgNO3) and hydrofluoric acid (HF) based solution. The results show that the reflectance of SiNWs can be modulated as a function of the lengths of the nanowires, and that these lengths can be modulated as a function of the chemical etching ratios. Experiments have shown that a reflectance coefficient as low as 1.2% can be achieved at certain visible wavelengths for the prepared SiNW structures.

Electrical properties of Barium Strontium Titanate thin films for embedded capacitor applications

This work focuses on the effect of deposition temperature and post deposition annealing (PDA) in different gas ambient on the electrical properties of R.F. sputter deposited ferroelectric Barium Strontium Titanate (Ba0.5Sr0.5TiO3) thin film capacitors. Approximately 2000Å of Barium Strontium Titanate (BST) thin film was deposited at different substrate temperatures (400, 450, 500 and 550°C) on cleaned silicon substrates. These BST films were then annealed separately in 100% N2, 100% O2 and 10% O2 + 90% N2 at 575°C in the same sputtering system (PVD anneal) as well as in a tube furnace.