posted on 2023-12-20, 14:04authored byFlorian
M. Schenk, Till Zellweger, Dhananjeya Kumaar, Darijan Bošković, Simon Wintersteller, Pavlo Solokha, Serena De Negri, Alexandros Emboras, Vanessa Wood, Maksym Yarema
Phase-change memory
(PCM) is an emerging memory technology based
on the resistance contrast between the crystalline and amorphous states
of a material. Further development and realization of PCM as a mainstream
memory technology rely on innovative materials and inexpensive fabrication
methods. Here, we propose a generalizable and scalable solution-processing
approach to synthesize phase-change telluride inks in order to meet
demands for high-throughput material screening, increased energy efficiency,
and advanced device architectures. Bulk tellurides, such as Sb2Te3, GeTe, Sc2Te3, and TiTe2, are dissolved and purified to obtain inks of molecular metal
telluride complexes. This allowed us to unlock a wide range of solution-processed
ternary tellurides by the simple mixing of binary inks. We demonstrate
accurate and quantitative composition control, including prototype
materials (Ge–Sb–Te) and emerging rare-earth-metal telluride-doped
materials (Sc–Sb–Te). Spin-coating and annealing convert
ink formulations into high-quality, phase-pure telluride films with
preferred orientation along the (00l) direction. Deposition engineering
of liquid tellurides enables thickness-tunable films, infilling of
nanoscale vias, and film preparation on flexible substrates. Finally,
we demonstrate cyclable and non-volatile prototype memory devices,
achieving performance indicators such as resistance contrast and low
reset energy on par with state-of-the-art sputtered PCM layers.