Novel k-restoring scheme for damaged ultra-low-k materials

• Published in: Microelectronic engineering Vol. 112; pp. 63 - 66
• Main Authors: Böhm, O., Leitsmann, R., Plänitz, Ph, Oszinda, T., Schaller, M., Schreiber, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-12-2013; Elsevier
• Subjects: Ab initio; Applied sciences; Carbon; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Damage; Depletion; DFT; Diffusion; Diffusion in nanoscale solids; Diffusion in solids; Display; Electron states; Electronics; Exact sciences and technology; Fractures; k-Restoring; Mathematical analysis; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Methods of electronic structure calculations; Microelectronics; Physics; Repair; Siloxanes; Transport properties of condensed matter (nonelectronic); ULK; Ultra low k; Ab initio; Ultra low k; DFT; k-Restoring; ULK; Water; Performance evaluation; Discrete Fourier transformation; Polymerization; Vision system; Carbon; Porous material; Hydroxyl group; Density functional method; Ab initio calculations; Diffusion; Low k dielectric; Helmet mounted displays; Damaging
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2013.05.017

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•From different repair chemicals bis(dimethyl)diacetoxysilane is the most effective.•Efficiency of the second reaction step depends on the distribution of the OH-groups.•If the second reaction step cannot occur, the repair chemical can react with water.•The reaction with water molecules leads to additional carbon depletion (anti-repair).•The anti-repair process can avoided by using a combination of repair chemicals.
In this study we have investigated the silylation of hydroxyl groups in carbon depleted ultra-low-k materials with different silylation agents – the so called k-restoring process. All calculations are based on density-functional theory using a GGA-PBE functional. We have compared the silylation performance of several silylation agents with respect to thermochemical parameters and the size of the molecules, which is a restricting factor for the diffusion inside porous ultra-low-k materials. Under these circumstances bis(dimethylamino)dimethylsilane (DMADMS) is one of most promising silylation agents. We have also studied additionally undesirable side reactions. We found that the usage of repair chemicals with two reactive groups can lead to a polymerisation of siloxane chains and a carbon depletion in the presence of water. Therefore, we have developed a novel k-restoring scheme, where we recommend the combined usage of repair chemicals with one and two reactive groups. We have shown that the most effective combination is hexamethyldisilazane (HMDS) and DMADMS.