Investigating the Impact of the Spatial Arrangement of the Terminal Methyl Group Relative to the Bridging Ethylene Group on the Properties of PMO Films
Year: 2025
Type: article
Abstract: The impact of the spatial arrangement of the terminal methyl group relative to the bridging ethylene group on the properties of PMO films has been studied using BTMSE-MTMS and TESDEMSE-MTMS precursors containing C–C bridging groups. TESDEMSE features a Si-attached CH3 group within the same molecule, forming hydrophobic films independently of MTMS concentration. Pure BTMSE-based films are hydrophilic and exhibit an increased dielectric constant due to water adsorption. The addition of MTMS to BTMSE introduces CH3 into the films, rendering them hydrophobic. The mechanical properties of the films do not exhibit a significant dependence on the location of CH3 groups. Thus, the spatial arrangement of CH3 relative to C–C significantly affects hydrophobicity, dielectric properties, thermal stability, and porosity. TESDEMSE demonstrates potential as a single precursor for low-k film deposition. However, annealing (curing) at 430 °C reduces the concentration of C–C bonds, and this phenomenon is more pronounced in TESDEMSE-based films. Quantum chemical analysis indicates that the ethylene bridge is generally weaker than the terminal methyl group, with the presence of an adjacent methyl group further decreasing its stability. The low thermal stability of these films poses a challenge for certain practical applications.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: Russian Science Foundation
Award: G2573971816
OpenAlex ID: W4409146390