Interdiffusion studies for HfSixOy and ZrSixOy on Si

Abstract

Metal incorporation into silicon substrates, and thermal stability of alternate gate dielectric candidates HfSixOy and ZrSixOy films after aggressive thermal annealing are reported. Considerable Zr incorporation is observed after furnace and rapid thermal annealing. No detectible Hf incorporation is observed for HfSixOy films annealed with the same conditions as the ZrSixOy films. Sputter deposited Hf silicate films showed superior thermal stability compared with chemical vapor deposited Zr silicate films. An alternate approach to obtain sub-nm resolution depth profiling of impurities in Si is also reported. Device performance associated with Zr incorporation into the channel is also discussed.