Conduction mechanism versus annealing in SiO2 films with Ge nanoparticles

摘要

This paper analyses and discusses the effect of Ge/Si atomic ratio and annealing temperature on the conduction mechanisms governing the electrical behavior of Ge-SiO2 films containing Ge nanoparticles embedded in amorphous SiO2 matrix. For this, the experimental conductance-temperature curves are modeled in correlation with the microstructure findings for two types of films. One type of films has a lower Ge/Si ratio of 0.73 and was obtained by magnetron sputtering followed by annealing in H2, at 500 °C, while the second one has a higher ratio of 1.86 and was obtained also by sputtering, but was annealed in N2, at 800 °C. Both types of films show an electrical behavior with a T^1/4 conductance dependence on temperature, typical for hopping mechanism.