Electron transport in Ta nanolayers: Application to tantalum capacitors

Tantalum pent oxide thin films are used as dielectric layers for capacitors, gate insulating layers for MOSFETS, RF MEMS switches, etc. Charge carriers transport mechanism and charge storage in insulating layer are important parameters for the application in these de-vices. Ta205 films show good electrical and dielectric properties for considered applications and low leakage current density value 4x10-8A/cm2 for the electric field 2 MV/cm. Dominant mechanism of charge carriers' transport is ohmic conduction for the low electric field, while Pool-Frenkel mechanism become dominant for electric field in the range 1 to 2.5 MV/cm. Tunneling current component is comparable with Pool-Frenkel current component or be-come dominant for electric field higher than 2 MV/cm at temperature lower then 200 K.