Non-aqueous electrodeposition of functional semiconducting metal chalcogenides: Ge₂Sb₂Te₅ phase change memory

Abstract

We report a new method for electrodeposition of device-quality metal chalcogenide semiconductor thin films and nanostructures from a single, highly tuneable, non-aqueous electrolyte. This method opens up the prospect of electrochemical preparation of a wide range of functional semiconducting metal chalcogenide alloys that have applications in various nano-technology areas, ranging from the electronics industry to thermoelectric devices and photovoltaic materials. The functional operation of the new method is demonstrated by means of its application to deposit the technologically important ternary Ge/Sb/Te alloy, GST-225, for fabrication of nanostructured phase change memory (PCM) devices and the quality of the material is confirmed by phase cycling via electrical pulsed switching of both the nano-cells and thin films.

Towards a 3D GeSbTe phase change memory with integrated selector by non-aqueous electrodeposition

“…This paper is organised as follows. In the next section, "Electrodeposited Phase Change Memory", we will show our previous results on the electrical characteristics of thin film and confined nano-cells of Ge-Sb-Te phase change memory, 12 now supported by a detailed transmission electron microscopy analysis of the composition and elemental distribution of the confined cells. The "Non-aqueous Electrodeposition from Non-Coordinating Solvents" section, will explain the rationale behind the solvent, electrolyte and precursor selection.…”

“…1). 12 The fabrication was undertaken by either patterning the top TiN electrode directly on the Ge-Sb-Te thin film (Fig. 1a) or filling etched SiO2 nanoholes with Ge-Sb-Te by electrodeposition on TiN bottom electrodes and subsequently patterning the top TiN electrode (Fig.…”

“…In our recent paper we presented an electrodeposition method based on a novel non-aqueous electrolyte. 12 The electrodeposition of phase change alloys becomes accessible thanks to suitably tailored, highly soluble precursor compounds containing the relevant elements. The non-aqueous electrolyte has a wider electrochemical window than water, facilitating the deposition of Ge, and allowing us to demonstrate cycling of electrodeposited Ge-Sb-Te phase change memory in 100 nm confined cells.…”

Hexahalometallate salts of trivalent scandium, yttrium and lanthanum: cation–anion association in the solid state and in solution

“…Raman: 240 cm À1 (A 1g [LaCl 6 ] 3À ). 1 X-ray experimental. Crystals suitable for single crystal X-ray analysis were obtained as described above.…”

Ferromagnetic-like behaviour in bismuth ferrite films prepared by electrodeposition and subsequent heat treatment

“…Besides its obvious use for the growth of pure metals and metallic alloys, electrodeposition is a powerful methodology that can be utilized for the preparation of semiconducting metal oxides, hydroxides and chalcogenides, either in the form of lms or nanostructures. [33][34][35][36] So far, investigation on BFO electrodeposition has been very scarce and the results have not been fully satisfactory in the sense that they lack a clear and unambiguous structural characterisation. [37][38][39] Moreover, in these previous works, emphasis was laid on the electrochemical performance of the materials (i.e., BFO nanoake and thin lms electrodes were applied in supercapacitor applications).…”