Álvaro del Prado | Searcharxiv

arXiv2024

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

AmorphousGd2O3 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.

cond-mat.mtrl-sci↗

arXiv2024

High Pressure Sputtering For Kigh-k Dielectric Deposition. Is It Worth Trying?

Our research group studies the deposition of high permittivity dielectrics by a non-standard method: high-pressure sputtering. The dielectrics studied here are gadolinium scandate deposited from dielectric targets, and gadolinium oxide deposited from a metallic target, with an in situ plasma oxidation. The stoichiometric gadolinium scandate presents a slight permittivity boost after annealing, but with gadolinium-rich scandate (grown with an annealing of a nanolaminate) the dielectric shows a high effective permittivity of 21 and no noticeable SiO2 layer at the interface with Si. On the other hand, the stacks fabricated with the metallic Gd target have a SiO2 interface less than 0.7 nm thick that can be further reduced by scavenging with Ti gates. In fact, this scavenging effect is also demonstrated for the first time with indium phosphide substrates, obtaining a low capacitance equivalent thickness of only 2.1 nm.

physics.app-ph↗