Vacuum treatment to stabilize oxidation at low temperature region in porous silicon

Abstract

Oxidation in porous silicon is studied for as-etched samples and samples subjected to high vacuum at room temperature. Attenuated Total Reflectance (ATR) measurements in infrared spectroscopy for temperatures ranging from 21 °C to 201 °C show two behaviors concerning oxide evolution: at temperatures below 100–130 °C, oxidation proceeds very slowly, and slower in the case of vacuum treated samples. It is believed that moisture extraction from the pores in vacuum medium is responsible for this enhanced behavior. Optical measurements show that nanostructures resident in the samples are not affected morphologically, although their surfaces exhibit a relatively low oxidation increase, lower for the vacuum treated samples, in accordance with the infrared results.