Permittivity enhancement of aluminum oxide thin films with the addition of silver nanoparticles

Multilayer reactive electron-beam evaporation of thin aluminum oxide layers with embedded silver nanoparticles (Ag-nps) has been used to create a dielectric thin film with an enhanced permittivity. The results show a frequency dependent increase of the dielectric constant kappa. Overall stack kappa of the control sample was found to be 7.7-7.4 in the 1 kHz-1 MHz range. This is in comparison with kappa=16.7-13.0 over the same frequency range in the sample with Ag-nps. Capacitance-voltage and conductance-voltage measurements indicate the presence of charge capture resulting from the Ag-nps. The authors attribute this dielectric constant enhancement to dipole and space charge polarization mechanisms. (c) 2006 American Institute of Physics.