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.

Modification Pathways for Copoly(2-oxazoline)s Enabling Their Application as Antireflective Coatings in Photolithography.

Chromophore-functionalized copoly(2-oxazoline)s are successfully evaluated as bottom antireflective coatings (BARCs) in high-resolution photolithography. With respect to UV light sources used in photolithographic production routines, anthracene is chosen as a chromophore. For application as polymer in BARCs, the copolymer poly(2-ethyl-2-oxazolin)45 -stat-poly(2-dec-9'-enyl-2-oxazolin)20 -stat-poly(2-(3'-(1"-(anthracen-9-ylmethyl)-1",2",3"-triazol-4-yl)propyl)-2-oxazolin)35 can be synthesized by the Huisgen cycloaddition click reaction of the copolymer poly(2-ethyl-2-oxazolin)45 -stat-poly(2-dec-9'-enyl-2-oxazolin)20 -stat-poly(2-pent-4'-inyl-2-oxazolin)35 and the corresponding azide-functionalized anthracenes. These copolymers can be crosslinked by the thermally induced thiol-ene reaction involving the unsaturated C=C bonds of the poly(2-dec-9'-enyl-2-oxazoline) repetition units and a multifunctional thiol as crosslinker. Tests of this BARC in a clean room under production conditions reveal a significant decrease of the swing-curve of a chemically amplified positive photoresist by more than 50%, hence significantly increasing the resolution of the photoresist.

Surface roughness of one nanofill and one silorane composite after polishing.

The aim of this study was to compare the roughness of the surface of one nanofill (Filtek Supreme XT 3M Espe, St. Paul, USA) and one silorane (Filtek Silorane, 3M Espe, St. Paul, USA) composite after polishing. Five specimens of each composite were polymerized under a polyester strip for 40 seconds. After curing four probes were polished with different Sof-Lex discs and one probe with Pogo for ten seconds. For the surface appointment a contact stylus profilometer was used. The profilometer made ten tracings for each sample at different locations. There was a significant difference in roughness between both composites. The Ra (average surface roughness) results for the silorane composite were almost always significantly higher than for the nanofill composite (T-test). For both composites Sof-Lex fine and superfine discs produced smoother final surfaces than Pogo. The nanofill composite used showed the smoothest surfaces after the polishing and finishing procedures.