Thermal Oxidation of Sputtered TaN Films and Properties of the Oxidized Films

Abstract

The thermal oxidations of a sputtered TaN film and the properties of an oxidized TaN (TaNO) film were investigated. By oxidation at around 600°C in dry oxygen, conductive TaN converts into an amorphous insulator which develops, after subsequent annealing at about 800°C, to a mixed compound consisting of main hcp Ta2O5 and amorphous nitride phases. The oxidation is controlled by a diffusion process. Capacitance measurements yield a relative dielectric constant of about 20. The dielectric breakdown strength is more than 2×106 V/cm. The TaNO film was found to be very suitable as a capacitor-forming material for microwave GaAs ICs in conformity with a self-align Au/TaN/WN/GaAs gate FET process.

Interpretation of the Changing the Band Gap of Al2O3 Depending on Its Crystalline Form: Connection with Different Local Symmetries

“…The samples were prepared on the identically treated [IMECcleaned] n-type Si(100) surfaces, as described in details elsewhere. 36,37 Annealing at 1000 °C for 60 s in a nitrogen atmosphere resulted in the crystallization of the amorphous film in the γ phase.…”

“…Am- Al 2 O 3 and γ- Al 2 O 3 films with thickness 12 nm were grown by atomic layer deposition (ALD) technique from trimethylaluminum Al­(CH 3 ) 3 and water precursors at 300 °C. The samples were prepared on the identically treated [IMEC-cleaned] n-type Si(100) surfaces, as described in details elsewhere. , Annealing at 1000 °C for 60 s in a nitrogen atmosphere resulted in the crystallization of the amorphous film in the γ phase.…”