Poly(ferrocenylsilanes) with controlled macromolecular architecture by anionic polymerization: Applications in patterning and lithography

Abstract

In this chapter, the versatility of poly(ferrocenylsilanes) (PFSs) as resists in reactive ion etching (RIE) for nanofabrication is presented. PFSs, belonging to the class of organometallic polymers, possess skeletal ferrocene and alkylsilane units which provide these solution-processable materials with a very high RIE resistance. First, it is shown that among the different paths for synthesizing PFS, anionic polymerization creates an opportunity to produce well-defined PFSs with a targeted molar mass and low polydispersity. Block copolymers and more complex structures can also be realized, which leads to exciting openings in maskless selfassembly lithography for nanopatterning. Then, optimization of the etching process, aimed at maximizing aspect ratios for PFS-based resists, is discussed. Next, several micro-and nanofabrication processes, using PFS homopolymers to fabricate nanoscale structures, are demonstrated. Finally, phase separation of PFS block copolymers and their use as self-assembled resists with long-range guided order in nanolithography is discussed. With this technique, various nanopatterns useful for CMOS design could be obtained.