Amorphous Lanthanum Lutetium Oxide Thin Films as an Alternative High-k Material

Abstract

Lanthanum lutetium oxide thin films have been grown on Si substrates by three different techniques: pulsed-laser deposition, molecular beam deposition, and atomic layer deposition. Post-deposition annealing in O2 was performed to improve their electrical properties. Capacitance-voltage and current-voltage measurements reveal well-behaving C-V curves and low leakage current density levels. Most strikingly, a dielectric constant around 30 could be achieved for amorphous thin films of this material. These results are discussed in terms of the microstructural characteristics of the films before and after thermal treatment.

Electrical and Structural Properties of Ternary Rare-Earth Oxides on Si and Higher Mobility Substrates and their Integration as High-k Gate Dielectrics in MOSFET Devices

“…The achievement of an stoichiometric content (i.e. ~1.5 oxygen atoms per metal atom) could be obtained by thermally treating them after growth [38,40,48]. In parallel to the oxygen reduction, an improvement on the dielectric properties of the films was observed.…”

“…The metal depositions were performed at room temperature (R.T.) and ex-situ. This is proven to not cause deleterious effects to the electrical properties [40]. Contrary to binary oxides [41], ternary RE oxides do not present an intense hygroscopic behavior after exposure to the ambient.…”

Growth, characterization, and transport properties of ternary (Bi1−xSbx)2Te3topological insulator layers

“…For the sample with an Sb content of 43% we fabricated a gate electrode covering the complete Hall bar. As a high-k gate dielectric an amorphous 100 nm thick LaLuO 3 layer grown by pulsed laser deposition was used [33].…”

Growth, characterization, and transport properties of ternary (Bi1-xSbx)2Te3 topological insulator layers

“…As a high-k gate dielectric an amorphous 100 nm thick LaLuO 3 layer grown by pulsed laser deposition was used. 33 The magnetotransport measurements were carried out in a variable temperature insert at temperatures down to 1.8 K. The magnetic field of up to 13.5 T was oriented perpendicularly to the sample surface. All measurements were performed in a four-terminal configuration using standard lock-in technique with an AC current of up to I = 25 µA.…”