Influence of oxygen content on the structural and electrical characteristics of thin neodymium oxide gate dielectrics

Abstract

Optical, electrical, and structural characteristics of yttrium oxide films deposited on plasma etched silicon substrates J.The structural properties and electrical characteristics of thin Nd 2 O 3 gate oxides were deposited on silicon substrates by reactive rf sputtering. The structural and morphological features of these films were studied, as a function of the growth conditions ͑three various argon-to-oxygen flow ratios: 20/ 5, 15/ 10, and 12.5/ 12.5 and temperature from 600 to 800°C͒, by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy. It is found that Nd 2 O 3 dielectrics with a 12.5/ 12.5 ratio condition annealed at 700°C exhibit a thinner capacitance equivalent thickness and excellent electrical properties, including the electric breakdown field, the interface trap density, the hysteresis, and frequency dispersion in the capacitance-voltage curves. This condition is suggested to the reduction of the interfacial SiO 2 and silicate formation, and the small of surface roughness due to the optimization of oxygen in the metal oxide film.

Influence of postdeposition annealing on structural properties and electrical characteristics of thin Tm2O3 and Tm2Ti2O7 dielectrics

“…The as-deposited sample for Tm 2 O 3 film has high level of thulium as compared to the annealed sample. This result is due to the formation of silicate film during thermal annealing, which is in agreement with the literature reported [5][6][7]. In contrast, the Tm 2 Ti 2 O 7 film annealed at 700 and 800 8C has the highest thulium of all samples examined, as shown in Fig.…”

“…The HfO 2 -based dielectric is likely to employ within this process technology, but it is widely believed that HfO 2 -based technology permits the downscaling of equivalent oxide thickness no further than below $0.8 nm [4]. In addition to the HfO 2 -based dielectrics, rare-earth (RE) metal oxide, such as La 2 O 3 , Pr 2 O 3 , Nd 2 O 3 , Gd 2 O 3 , Dy 2 O 3 , and Er 2 O 3 [5][6][7][8][9][10], is being considered as one of the most promising high-k materials due to its superior properties including a high dielectric constant, a large bandgap, and good thermal stability in contact with the Si substrate. However, the moisture absorption is a major problem with RE oxides, leading to a thicker film and a larger flat-band voltage shift [11].…”

Integrations and challenges of novel high-k gate stacks in advanced CMOS technology

“…Although Hf-based high-k gate dielectrics have been intensively investigated as candidate for conventional SiO 2 , recently much attention are also given to the rare earth oxides M 2 O 3 (M = La, Pr, Gd and Nd) due to their large band-gaps, high dielectric constants, small lattice mismatch with Si, and good thermodynamic stability in direct contact with Si [194][195][196][197]. Base on the observations from different groups, improved interface stability and reduced leakage currents can be achieved by forming the amorphous silicate as candidates.…”

Influence of oxygen content on the structural and pH-sensitive properties of thin Nd<inf>2</inf>O<inf>3</inf> electrolyte-insulator-semiconductor

“…Nd 2 O 3 thin film has attracted much attention as a sensing membrane because it has the advantages of high-k value, good lattice matching, and thermodynamical stability with Si substrate [6]. Furthermore, we demonstrated that Nd 2 O 3 dielectrics exhibited excellent electrical properties, including a high electric breakdown field, a low interface trap density, a small hysteresis and frequency dispersion [7].…”