Microstructural, optical and electrical properties of GeO₂ thin films prepared by sol‐gel method

Abstract

GeO 2 thin films were prepared by sol-gel method on ITO/Glass substrate. The electrical and optical properties and the microstructures of these films were investigated with special emphasis on the effects of an annealing treatment in ambient air. The films were annealed at various temperatures from 500 °C to 700 °C. Structural analysis through X-ray diffraction (XRD) and atomic force microscope (AFM) showed that surface structure and morphological characteristics were sensitive to the treatment conditions. The optical transmittance spectra of the GeO 2 /ITO/Glass were measured using a UV-visible spectrophotometer. All films exhibited GeO 2 (101) orientation perpendicular to the substrate surface where the grain size increased with increasing annealing temperature. The optical transmittance spectroscopy further revealed high transparency (over 70%) in the wave range 400 -800 nm of the visible region. At an annealing temperature level of 700 °C, the GeO 2 films were found to possess a leakage current density of 1.31×10-6 A/cm 2 at an electrical field of 20 kV/cm.

Influence of oxygen flow rate on the surface chemistry and morphology of radio frequency (RF) magnetron sputtered zinc oxide thin films

“…This temperature was selected on the basis of the structure zone (SZM) model. If T s is the substrate temperature and T m is the melting point of the material, then according to the SZM, a ratio of T s / T m > 0.3 represents the transition from low surface diffusion with porous structure to high surface diffusion with denser structure . For ZnO, with T m = 2248 K, a substrate temperature of 400 °C = 673 K, yields a ratio of T s / T m = 0.3, i.e.…”

Understanding the Formation of Elemental Germanium by Thermolysis of Sol-Gel Derived Organogermanium Oxide Polymers

“…Recent reports suggesting GeO 2 as a high-k dielectric make studying its phase stability of great import to the electronics industry. 34,35 In this regard, it is particularly important to understand the thermal properties of germanium oxides and their evolution at temperatures below 425 °C (i.e., the thermal budget of a CMOS chip). 36 Sol-gel derived materials are convenient precursors for preparing germanium oxide-embedded Ge-NCs.…”

“…In this context, Ge-NCs embedded in low-k (e.g., SiO 2 ) , as well as high-k (e.g., HfO 2 ) dielectrics have been investigated. Recent reports suggesting GeO 2 as a high-k dielectric make studying its phase stability of great import to the electronics industry. , In this regard, it is particularly important to understand the thermal properties of germanium oxides and their evolution at temperatures below 425 °C (i.e., the thermal budget of a CMOS chip) …”