Embedded ferroelectric nanostructure arrays

Abstract

Ferroelectrics hold promise for high-density non-volatile data storage device use. Their eventual performance will strongly depend on the available displacement current, which primarily scales with the area but might to some extent be enhanced by substrate-induced homogeneous strain while the interface at the same time controls the coercive field. As the lateral dimensions persistently decrease, the only way to keep track of the real figures of merit with realistic electrodes is to use a macroscopic configuration instead of scanning probe approaches with undefined interfaces. We report on a novel approach to integrating arbitrarily patterned, highly registered ferroelectric nanoislands fabricated by a template controlled chemical solution deposition approach into a matrix of a low-k dielectric spin-on glass. These structures with a narrow lateral size distribution below 100 nm are subsequently polished in a chemical-mechanical polishing step to expose their very tops, whose piezoelectrically active area depends on the polishing time. At this stage our findings indicate a full piezoelectric functionality of the locally exposed nanoislands. The structures are ready for macroscopic top electrodes to average the displacement current over hundreds of almost identical structures, to provide a nanoscale scaling behaviour of the individual ferroelectric capacitors.

Individual switching of film-based nanoscale epitaxial ferroelectric capacitors

“…[4][5][6][7][8][9][10][11][12] Several different fabrication methods such as chemical solution deposition, focused ion-beam ͑FIB͒, and e-beam lithography have been used for ferroelectric nanostructure fabrication. [6][7][8][9][10][11][12][13][14][15] FIB has been almost exclusively used to fabricate ferroelectric capacitors. However, the area near the surface can be damaged during processing.…”

Rapid Nanoimprinting and Excellent Piezoresponse of Polymeric Ferroelectric Nanostructures

“…Ferroelectric materials are promising for a wide range of applications, including sensing and actuation, , data storage, − photonics, spintronics, and energy conversion and storage. , With the ever-increasing demand for miniaturization of electronic and photonic devices, there have been tremendous efforts in developing nanostructured ferroelectric patterns with smaller feature size, higher density, and improved sensitivity and functionality . Various techniques have been developed to pattern ferroelectric nanostructures, including focused ion beam (FIB) milling, − E-beam lithography writing, soft lithography, and self-assembling. , While top-down types of approaches such as FIB milling and E-beam writing are able to create regular arrays of ferroelectric patterns, they are expensive, slow, and difficult to pattern a large area.…”

Ferroelectric nanoparticles, wires and tubes: synthesis, characterisation and applications

“…89 Huang et al 90 also fabricated well-ordered PtO x /PZT/PtO x arrays of capacitors, down to a cell size of 90 Â 90 nm, using EBL and plasma etching with a photoresist mask. Clemens et al 87 have produced polycrystalline arrays of PbTiO 3 nanoislands (lateral dimensions $50 to 100 nm) using EBL assisted synthesis. Nguyen and co-workers demonstrated the wafer-scale production of laterally ordered 40 nm PZT nanowires, using a 'photolithography and etching for nanoscale lithography' (PENCiL) technique.…”