title: Laser-induced nondestructive patterning of a thin ferroelectric polymer film with controlled crystals using Ge8Sb2Te11 alloy layer for nonvolatile memory.
abstract: We present a simple but robust nondestructive process for fabricating micropatterns of thin ferroelectric polymer films with controlled crystals. Our method is based on utilization of localized heat arising from thin Ge(8)Sb(2)Te(11) (GST) alloy layer upon exposure of 650 nm laser. The heat was generated on GST layer within a few hundred of nanosecond exposure and subsequently transferred to a thin poly(vinylidene fluoride-co-trifluoroethylene) film deposited on GST layer. By controlling exposure time and power of the scanned laser, ferroelectric patterns of one or two microns in size are fabricated with various shape. In the micropatterned regions, ferroelectric polymer crystals were efficiently controlled in both degree of the crystallinity and the molecular orientations. Nonvolatile memory devices with laser scanned ferroelectric polymer layers exhibited excellent device performance of large remnant polarization, ON/OFF current ratio and data retention. The results are comparable with devices containing ferroelectric films thermally annealed at least for 2 h, making our process extremely efficient for saving time. Furthermore, our approach can be conveniently combined with a number of other functional organic materials for the future electronic applications.
authors.affiliation: Department of Materials Science and Engineering, Yonsei University , Seoul 120749, Republic of Korea.
authors.forename: Insung
authors.initials: I
authors.lastname: Bae
authors.forename: Richard Hahnkee
authors.initials: RH
authors.lastname: Kim
authors.forename: Sun Kak
authors.initials: SK
authors.lastname: Hwang
authors.forename: Seok Ju
authors.initials: SJ
authors.lastname: Kang
authors.forename: Cheolmin
authors.initials: C
authors.lastname: Park
keywords: Ge8Sb2Te11 alloy layer; PVDF-TrFE; ferroelectric polymer; laser-induced writing; nondestructive patterning; nonvolatile polymer memory