Theoretical investigation of in situ k-restore processes for damaged ultra-low-k dielectrics

• Bis(dimethylamino)-dimethylsilane (DMADMS) fragments primary to Si(CH3)3
• Octamethylcyclotetrasiloxane (OMCTS) fragments primary to SiO(CH3)2
• The favored fragments of OMCTS are very effective repair fragments.
• Plasma repair is less effective for DMADMS due to its lack of oxygen.

Ultra-low-k (ULK) materials are essential for today's production of integrated circuits (ICs). However, during the manufacturing process, the ULK's low dielectric constant (k-value) increases due to the replacement of hydrophobic species with hydrophilic groups. We investigate the use of plasma enhanced fragmented silylation precursors to repair this damage. The fragmentation of the silylation precursors octamethylcyclotetrasiloxane (OMCTS) and bis(dimethylamino)-dimethylsilane (DMADMS) and their possible repair reactions are studied using density functional theory (DFT) and molecular dynamics (MD) simulations.

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