Poly(styrene)- block-Maltoheptaose Films for Sub-10 nm Pattern Transfer: Implications for Transistor Fabrication
Journal
ACS Applied Nano Materials
Date Issued
2021
Author(s)
Löfstrand, Anette
Jafari Jam, Reza
Mothander, Karolina
Nylander, Tommy
Mumtaz, Muhammad
Vorobiev, Alexei
Borsali, Redouane
Maximov, Ivan
Abstract
Sequential infiltration synthesis (SIS) into poly(styrene)-block-maltoheptaose (PS-b-MH) block copolymer using vapors of trimethyl aluminum and water was used to prepare nanostructured surface layers. Prior to the infiltration, the PS-b-MH had been self-assembled into 12 nm pattern periodicity. Scanning electron microscopy indicated that horizontal alumina-like cylinders of 4.9 nm diameter were formed after eight infiltration cycles, while vertical cylinders were 1.3 nm larger. Using homopolymer hydroxyl-terminated poly(styrene) (PS-OH) and MH films, specular neutron reflectometry revealed a preferential reaction of precursors in the MH compared to PS-OH. The infiltration depth into the maltoheptaose homopolymer film was found to be 2.0 nm after the first couple of cycles. It reached 2.5 nm after eight infiltration cycles, and the alumina incorporation within this infiltrated layer corresponded to 23 vol % Al2O3. The alumina-like material, resulting from PS-b-MH infiltration, was used as an etch mask to transfer the sub-10 nm pattern into the underlying silicon substrate, to an aspect ratio of approximately 2:1. These results demonstrate the potential of exploiting SIS into carbohydrate-based polymers for nanofabrication and high pattern density applications, such as transistor devices. ? 2021 The Authors. Published by American Chemical Society.
Subjects
Aluminum oxide; Aspect ratio; Block copolymers; Cylinders (shapes); Scanning electron microscopy; Styrene; Hydroxyl-terminated; Nanostructured surface layer; Neutron reflectometry; Pattern periodicity; Preferential reaction; Silicon substrates; Trimethyl aluminums; Vertical cylinders; Alumina
Type
journal article