In the present work, the plasma repair for damaged ultra-low-k (ULK) materials, newly developed at the Fraunhofer ENAS, is studied with density functional theory (DFT) and molecular dynamic (MD) methods to obtain new insights into this repair mechanism. The ULK materials owe their low dielectric constant (k-value) to the insertion of k-value lowering methyl groups. During the manufacturing process, the ULK materials are damaged and their k-values increase due to the adsorbtion of hydroxyl groups (OH-damage) and hydrogen atoms (H-damage) that replaced themethyl groups.
The first investigation point is the creation of repair fragments. For this purpose the silylation molecules bis(dimethylamino)-dimethylsilane (DMADMS) and octamethylcyclotetrasiloxane (OMCTS) are fragmented. Here, only fragmentation reactions that lead to repair fragments that contain one silicon atom and at least one methyl group were considered. It is shown that the repair fragments that contain three methyl groups are preferred, especially in a methyl rich atmosphere.
The effectivity of the obtained repair fragments to cure an OH- and H-damage are investigated with two model systems. The first system consists of an assortment of small ULK-fragments, which is used to scan through the wide array of possible repair reactions. The second system is a silicon oxide cluster that investigates whether the presence of a cluster influences the reaction energies.
In both model systems, repair fragments that contain three methyl groups or two oxygen atoms are found to be most effective. Finally, the quantum chemical results are compared to experimental findings to get deeper insight into the repair process.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa.de:bsz:ch1-qucosa-160903 |
| Date | 16 February 2015 |
| Creators | Förster, Anja |
| Contributors | TU Chemnitz, Fakultät für Naturwissenschaften, Prof. Dr. Sibylle Gemming, Dr. Jörg Schuster, Prof. Dr. Sibylle Gemming, Prof. Dr. Stefan E. Schulz |
| Publisher | Universitätsbibliothek Chemnitz |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:masterThesis |
| Format | application/pdf, text/plain, application/zip |
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