Anodic formation and SEM characterization of zirconium oxide nanostructured films

Zirconium oxide (ZrO2) is a widely utilized inorganic material with excellent dielectric, optical, and biocompatible characteristics. The properties and areas of the ZrO2 applications can be further broadened by making the material nanostructured. In this work, anodic ZrO2 nanostructured films were developed and characterized by scanning electron microscopy. The films were prepared by anodizing magnetron-sputtered Al/Zr bilayers in two regimes: galvanostatic/potentiostatic anodizing in (COOH)2 and H2SO4 solutions (anodized films) and that followed by the high-speed reanodizing to a significantly higher anodic voltage (reanodized films). The growth of a porous anodic alumina (PAA) layer followed by PAA-assisted oxidation of the Zr underlayer was achieved. The anodized films consist of arrays of self-organized spatially ordered ZrO2 nanohillocks while the reanodized films comprise arrays of vertically aligned ZrO2 nanorods. The growth of amorphous ZrO2 nanohillocks and nanorods within the alumina pores via migration of Zr4+ cations is a unique situation for anodic films on zirconium, which normally grow crystalline and by O2- anion transport at the oxide/metal interface only. The achievement is a milestone towards understanding the ion transport during the PAA-assisted anodization of valve metals with low cation transport number

The planar anodic Al2O3-ZrO2 nanocomposite capacitor dielectrics for advanced passive device integration

The need for integrated passive devices (IPDs) emerges from the increasing consumer demand for electronic product miniaturization. Metal-insulator-metal (MIM) capacitors are vital components of IPD systems. Developing new materials and technologies is essential for advancing capacitor characteristics and co-integrating with other electronic passives. Here we present an innovative electrochemical technology joined with the sputter-deposition of Al and Zr layers to synthesize novel planar nanocomposite metal-oxide dielectrics consisting of ZrO2 nanorods self-embedded into the nanoporous Al2O3 matrix such that its pores are entirely filled with zirconium oxide. The technology is utilized in MIM capacitors characterized by modern surface and interface analysis techniques and electrical measurements. In the 95-480 nm thickness range, the best-achieved MIM device characteristics are the one-layer capacitance density of 112 nF center dot cm(-2), the loss tangent of 4 center dot 10(-3) at frequencies up to 1 MHz, the leakage current density of 40 pA center dot cm(-2), the breakdown field strength of up to 10 MV center dot cm(-1), the energy density of 100 J center dot cm(-3), the quadratic voltage coefficient of capacitance of 4 ppm center dot V-2, and the temperature coefficient of capacitance of 480 ppm center dot K-1 at 293-423 K at 1 MHz. The outstanding performance, stability, and tunable capacitors' characteristics allow for their application in low-pass filters, coupling/decoupling/bypass circuits, RC oscillators, energy-storage devices, ultrafast charge/discharge units, or high-precision analog-to-digital converters. The capacitor technology based on the non-porous planar anodic-oxide dielectrics complements the electrochemical conception of IPDs that combined, until now, the anodized aluminum interconnection, microresistors, and microinductors, all co-related in one system for use in portable electronic devices