Roughness and Uniformity Control during Wet Etching of Molybdenum

In this work the wet etching of molybdenum thin films was investigated for applications requiring controlled recess without roughening or pattern loading. First, continuous etching of Mo in alkaline and oxidative peroxide solutions was studied. Then, additives like glycine and diethylenetriamine were used and their effect on etch rate and roughness was assessed. Finally, we evaluated if the requirements for a stepwise etching approach for Mo recess using peroxide or ozonated water as the oxidizing step and ammonia as the oxide dissolution agent were met.

Thorium oxide dissolution in HNO3-HF mixture: kinetics and mechanism

This paper is an attempt to find out thorium oxide dissolution mechanism in HNO3-HF mixture. In a previous paper, several parameters effects on thorium oxide dissolution have been described, with specific focus on hydrofluoric acid effect, which can lead to an increase of the dissolution rate if present in small amount, but precipitates as ThF4 at higher content. Based on this previous study, experimental data were fitted using several dissolution models in order to find out the best one. Finally, a revisited model based on literature and considering the ThF4 formation was proposed. It describes the main steps of dissolution and is able to fit the experimental data for a wide range of solution compositions. This point is crucial since it allows considering an extrapolation of the established model to not-yet-studied conditions.

Poly-quasi-eutectic solvents (PQESs): versatile solvents for dissolving metal oxides

Versatile poly-quasi-eutectic solvents (PQESs), which own excellent metal oxide dissolution performance, have been synthesized.