Towards metal electrode interface scavenging of rare-earth scandates: A Sc2O3 and Gd2O3 study

Amorphous Gd2O3 and Sc2O3 thin films were deposited on Si by high-pressure sputtering (HPS). In order to reduce the uncontrolled interfacial SiOx growth, firstly a metallic film of Gd or Sc was sputtered in pure Ar plasma. Subsequently, they were in situ plasma oxidized in an Ar/O2 atmosphere. For post-processing interfacial SiOx thickness reduction, three different top metal electrodes were studied: platinum, aluminum and titanium. For both dielectrics, it was found that Pt did not react with the films, while Al reacted with them forming an aluminate-like interface and, finally, Ti was effective in scavenging the SiO2 interface thickness without severely compromising gate dielectric leakage.

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► Sc2O3 and Gd2O3 films were deposited by High-pressure sputtering.
► MIS devices were fabricated with Al, Pt and Ti electrodes.
► Pt does not affect the dielectric quality.
► Al reacts with the high-k dielectric.
► Ti produces an interface scavenging effect.