Reactive ion etching of cylindrical polyferrocenylsilane block copolymer micelles:: Fabrication of ceramic nanolines on semiconducting substrates

The diblock copolymers, poly(isoprene-block-ferrocenyldimethylsilane) (PI-b-PFDMS) and poly(ferrocenyldimethylsilane-block-dimethylsiloxane) (PFDMS-b-PDMS), form cylindrical micelles with an organometallic polyferrocenylsilane core in a solvent of hexanes. These cylindrical micelles were deposited onto a Si substrate from solution by either spin or dip coating, and upon reactive ion etching, continuous ceramic nanolines with lengths of micrometers and widths as small as 8 nm were created. The nanolines were characterized by scanning force microscopy (SFM) and transmission electron microscopy (TEM), and were shown to contain Fe, Si, and O from X-ray photoelectron spectroscopy (XPS) studies. The widths of the nanolines could be varied from ca. 8 to 30 nm, depending on the composition of the corona (PI or PDMS). The oriented deposition of these cylindrical micelles can be achieved along pre-patterned grooves on a resist film using capillary forces. Following treatment with hydrogen or oxygen plasma, oriented ceramic nanolines can be fabricated. The approach reported here represents a relatively simple method to create ceramic nanolines with large aspect ratio on semiconducting substrates.