Impact of Al, Ni, and TiN Metal Gates On ZrO2-MOS Capacitors

Abstract

We compare the impact of Aluminum, Nickel and Titanium-Nitride as gate materials on MOS caps incorporating metal organic chemical vapor deposited (MOCVD) ZrO2 .Post metallization annealing in forming gas atmosphere on the electrical characteristics of the various gate stacks is a further issue. Aluminum was primarily investigated as a reference material. Whereas TiN-stacks show very promising electrical characteristics necessary for future CMOS devices, Ni-MOS caps exhibit an undesired high frequency behavior.

MOCVD of HfO2 and ZrO2 high-k gate dielectrics for InAlN/AlN/GaN MOS-HEMTs

“…These impurities are most likely incorporated from the precursor substances during the deposition process. In an earlier work on Si substrates [14], we showed that after post-deposition annealing (PDA) at 650 • C that Auger analysis did not reveal any remaining impurities in the investigated films, and that the films exhibit a Zr/O ratio close to stoichiometric ZrO 2 . In order to minimize the applied thermal budget, no specific PDA has been applied in the present case, but the dielectrics have been subjected to the annealing of the Ohmic contacts.…”

“…Compositional results of our ZrO 2 and HfO 2 thin films deposited on silicon have been investigated by Auger electron spectroscopy, and in general exhibit carbon contamination of about 3%, as well as fluorine contamination of about [14]. These impurities are most likely incorporated from the precursor substances during the deposition process.…”