Fabrication, Characterization and Applications of Porous Silicon Thin Films and Multilayered Systems

Sammanfattning: Variable angle spectroscopic ellipsometry was used for characterization of single- as well as multilayered systems of porous silicon. In addition to the complex structures such as Bragg reflectors and Fabry-Pérot filters, more advanced continuos porosity profiles were manufactured in a controlled manner. Furthermore, the active role of HCl as an additional component in the HF-based electrolytes and its effects on the microstructural properties of the material were investigated. Generalized ellipsometry was employed in order to investigate optical anisotropy of the material. The effects of thermal oxidation on the microstructural as well as optical properties of various types of porous silicon structures were investigated. In addition, an improvement of the vapor sensitivity at temperatures lower than room-temperature was observed. Ellipsometry was utilized to in a quantitative manner investigate adsorption of proteins in the material.