Reaction behavior of anionic oxidizing agents in the metal assisted etching of silicon

• Applicant: Professor Dr. Jörg Acker
• Subject Area: Synthesis and Properties of Functional Materials ; Physical Chemistry of Solids and Surfaces, Material Characterisation ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314964421

The submitted project is addressed to the impact of anionic oxidizing agents on the reaction pathways of metal assisted silicon etching as well as to the reduction reactions of the oxidizing agents itself.The first topic in this investigation is devoted to the reactivity of anionic oxidizing agents against metal layers, in particular with the interactions of metal layers with anionic oxidizing agents and the reduction pathways of involved species. The second topic deals with typical reactions which are insufficiently explained in literature so far. These are the varying stoichiometric copper-silicon ratios while copper deposition on silicon, the behavior of perchlorate on metal-silicon composites and metal silicide phases, and the impact of halogenides on the degradation of anionic oxidizing agents. The third topic is focused on the investigation of current theories and models concerning the formation of hydrogen within silicon etching processes, hydrogen involved degradation processes of anionic oxidizing agents, and hole transfers from the metal surface to silicon.To study these phenomena series of different experiments are proposed for batch tests under well-defined conditions. By means of different analytical methods the compositions in the solid, liquid, and gaseous phases are quantified in order to identify the reduction pathway of the oxidizing agents, to monitor the found product distribution, and to determine kinetic parameters of the involved reactions. These data should be used to evaluate the current theories of metal-assisted etching of silicon, to improve them or to establish new models if it is required.

• DFG Programme: Research Grants