Area-selective atomic/molecular layer deposition via block copolymer approach: Zn-benzene dithiol deposition as a case study

We have developed a novel atomic/molecular layer deposition (ALD/MLD) process for the growth of essentially air-stable zinc-organic thin films from diethyl zinc and 1,4-benzene dithiol (BDT) precursors at an appreciably low deposition temperature of 60 °C. The low deposition temperature along with the high film growth rate of 3.96 Å/cycle achieved with relatively short precursor pulse lengths allowed us to employ the process for area-selective (AS) ALD/MLD on block copolymer (BCP) substrates, not challenged before. Our study showed that on the chosen polystyrene-b-poly(ethylene oxide) (PS-b-PEO) BCP substrates, the Zn-BDT film grows in an AS manner such that the growth most likely occurs preferentially on the PEO domains. We believe the BCP-based AS-ALD/MLD approach represents an alternative nanopatterning technique to the conventional photolithography, which could be highly beneficial particularly in next-generation flexible applications.