Fabrication of Amorphous Silicon-Carbon Hybrid Films Using Single-Source Precursors

The aim of this study was the preparation of different amorphous silicon-carbon hybrid thin-layer materials according to the liquid phase deposition (LPD) process using single-source precursors. In our study, 2-methyl-2-silyltrisilane (methylisotetrasilane; 2), 1,1,1-trimethyl-2,2-disilyltrisilane (trimethylsilylisotetrasilane; 3), 2-phenyl-2-silyltrisilane (phenylisotetrasilane; 4), and 1,1,2,2,4,4,5,5-octamethyl-3,3,6,6-tetrasilylcyclohexasilane (cyclohexasilane; 5) were utilized as precursor materials and compared with the parent compound 2,2-disilyltrisilane (neopentasilane; 1). Compounds 2-5 were successfully oligomerized at λ = 365 nm with catalytic amounts of the neopentasilane oligomer (NPO). These oligomeric mixtures (NPO and 6-9) were used for the preparation of thin-layer materials. Optimum solution and spin coating conditions were investigated, and amorphous silicon-carbon films were obtained. All thin-layer materials were characterized via UV/vis spectroscopy, light microscopy, spectroscopic ellipsometry, XPS, SEM, and SEM/EDX. Our results show that the carbon content and especially the bandgap can be easily tuned using these single-source precursors via LPD.