Electrical characteristics of mixed Zr–Si oxide thin films prepared by ion beam induced chemical vapor deposition at room temperature

Abstract

Mixed Zr–Si oxide thin films have been prepared at room temperature by ion beam decomposition of organometallic volatile precursors. The films were flat and amorphous. They did not present phase segregation of the pure single oxides. A significant amount of impurities (–C–, –CHx, –OH, and other radicals coming from partially decomposed precursors) remained incorporated in the films after the deposition process. This effect is minimized if the Ar content in the O2/Ar bombarding gas is maximized. Static permittivity and breakdown electrical field of the films were determined by capacitance–voltage and current–voltage electrical measurements. It is found that the static permittivity increases non-linearly from ~4 for pure SiO2 to ~15 for pure ZrO2. Most of the dielectric failures in the films were due to extrinsic breakdown failures. The maximum breakdown electrical field decreases from ~10.5 MV/cm for pure SiO2 to ~45 MV/cm for pure ZrO2. These characteristics are justified by high impurity content of the thin films. In addition, the analysis of the conduction mechanisms in the formed dielectrics is consistent to Schottky and Poole-Frenkel emission for low and high electric fields applied, respectively.