PERFORMANCE OF TANTALUM-SILICON-NITRIDE DIFFUSION-BARRIERS BETWEEN COPPER AND SILICON DIOXIDE

Amorphous, 10-nm-thick tantalum-silicon-nitride (TaSiN) layers were found to be effective diffusion barriers between copper and thermal silicon dioxide. The films were electrically evaluated using TaSiN/Cu/TaSiN-oxide-silicon capacitors and bias thermal stress (BTS) treatments; the capacitors were stressed at 300 degrees C with electric fields in excess of 1 MV/cm for up to 80 h. High frequency capacitance versus voltage characteristics were recorded at room temperature before and after BTS treatment. Based upon comparisons between these (C-V) curves, barrier failure was concluded to have not occurred. (C) 1995 American Institute of Physics.