Changes in Electronic Structure of La[sub x]Al[sub y]O Films as a Function of Postdeposition Annealing Temperature

Abstract

Amorphous La x Al y O films, containing 100, 50, and 30% La, were deposited by atomic layer deposition ͑ALD͒ on ultrathin SiO 2 films ͑1 nm͒. Changes in the depth profile, as a function of composition, and structure were examined by medium energy ion scattering and transmission electron microscopy. The electronic structure of the La x Al y O films was investigated by X-ray photoelectron spectroscopy as a function of La concentration and postdeposition annealing temperature. In the case of a pure La 2 O 3 film without Al 2 O 3 , the SiO 2 at the interfacial layer had been converted to SiO 2−x and La silicate during the ALD process. However, in case of a La 2 O 3 film with Al 2 O 3 , interfacial reactions were significantly suppressed. In particular, silicate formation in the La 2 O 3 films gradually increased with the increasing annealing temperature, while that in La 2 O 3 films incorporated Al 2 O 3 was suppressed up to an annealing temperature of 800°C.

Carrier Mobility Enhancement of Tensile Strained Si and SiGe Nanowires via Surface Defect Engineering

“…Surface defects can be critical for carrier scattering because the charge carrier on the surface of a nano structure is the main contributor to the conduction process, resulting in a degradation in conductivity . In order to change the chemical structure of the surface of NWs, an Al 2 O 3 shell was applied to the Si 1– x Ge x NWs to prevent the formation of surface oxidation defects using an atomic layer deposition (ALD) system (Figure S4) because Al 2 O 3 is a well-known barrier to the diffusion of externally supplied oxygen and the interfacial layer on the NW surface can be effectively removed at the initial ALD process in the Al 2 O 3 /Si system Figure a shows strain–stress curves for Si and SiGe NWs before and after Al 2 O 3 passivation.…”

Influences of different structures on the characteristics of H 2 O-based and O 3 -based La x Al y O films deposited by atomic layer deposition

“…The binding energy located at 99.3 eV is the Si 0 peak, which is attributed to the Si substrate. [24] The higher peaks indicated by black are satellite peaks. The green and red curves indicate Si 3+ and Si * +Si 4+ , respectively, which come from the silicates and SiO 2−x .…”

“…The green and red curves indicate Si 3+ and Si * +Si 4+ , respectively, which come from the silicates and SiO 2−x . [22,24] The shift of the peaks of the silicates indicates that the types of chemical bonds of silicates are different. For sample B, because of the existence of the SiO 2 barrier layer, the amount of silicates in the sample is smaller than that in sample A.…”

Effects of Rapid Thermal Annealing and Different Oxidants on the Properties of LaxAlyO Nanolaminate Films Deposited by Atomic Layer Deposition

“…The oxidants have great influences on the defects and residual impurities in the high- k film if the process conditions are optimized in ALD process. On the other hand, the effects of RTA on the properties of La x Al y O films have been reported [20, 21]. People found that the growth of the interface layer was suppressed and the properties of film were enhanced by RTA.…”