Structure of Block Copolymer and Polymer Brush Systems with an Investigation into the Infill Mechanism for the Fabrication of Metal Oxide Nanopatterns, Thin Films and Hard Etch Masks

Abstract

Block Copolymers (BCPs) have been recognised as a cost effective complimentary technique for traditional lithography in the semiconductor industry. They have been heavily investigated in this regard. However their ability to self-assemble also opens up a huge number of other potential applications. This thesis illustrates a use for BCPs as a template for incorporating metal oxide nanoscopic material for their functional use in various disciplines - e.g. catalysis, integrated circuits, and sensing devices. Here the fabrication of nanaowires of multiple metal oxide materials using asymmetric Polystyrene-block-poly-ethylene oxide (PS-b-PEO) and Polystyene-block¬-polymethyl metacrylate (PS-b-PMMA) systems. Control over orientations was achieved by Solvent Vapour Annealing (SVA). The contrast of low χ BCP systems has been one of the primary limiting factors preventing their implementation in more industrial fabrication processes. This is addressed in this thesis by creating a hard mask of Iron Oxide using a facile metal inclusion technique. Polymer brush systems are also included as a new method of selectively depositing metal oxide films on industrially relevant substrates. Selective area deposition of metal oxides films is also displayed with the use of polymer brush systems. This enables the deposition of these films exclusively on one substrate material, avoiding the other (e.g. copper and silicon patterned substrates). Existing selective area deposition techniques exist with the use of ALD and SIS, however the technique presented here offers large time and cost benefits over these techniques.