Paper TF+AS+SE+SS-MoA6
Quantitative In Situ Infrared Analysis of Reactions between Trimethylaluminum and Polymers during Al₂O₃ Atomic Layer Deposition

Monday, October 28, 2013, 3:40 pm, Room 104 A

The reactions of trimethylaluminum (TMA) toward substrates during the Al₂O₃ atomic layer deposition (ALD) on a variety of polymers were studied by in-situ Fourier transform infrared spectroscopy (FTIR). The experiments demonstrate that TMA reacts with certain nucleophilic functional groups on the polymer surface during the first several ALD cycles. For some polymer substrates, TMA vapor penetrates into the polymer and reacts in the polymer bulk. In both cases, the initial reaction plays an important role in the nucleation and growth of Al₂O₃. For chemically inert polymers nucleation of Al₂O₃ ALD is relative slow at the initial stage due to the lack of reactive groups on the substrate. However, polyester, polyamide and polyether are more reactive, and in-situ FTIR spectra showed a larger extent of reaction with TMA, facilitating the nucleation of ALD film on these polymers. By comparing FTIR spectra, we quantitatively estimate the extent of TMA reaction towards different polymers, and confirmed the results using X-ray photoelectron spectroscopy and scanning electron microscopy. Results give insight into the importance of polymer structure in determining the nature and extent of reaction during ALD film processing on polymer substrates.