Atomic layer deposition

About: Atomic layer deposition is a research topic. Over the lifetime, 19821 publications have been published within this topic receiving 477332 citations. The topic is also known as: ALD.

Field Effects in Plasmonic Photocatalyst by Precise SiO2 Thickness Control Using Atomic Layer Deposition

Abstract: We report on TiO2 thin films with superior photocatalytic efficiency due to an increase in its exciton carrier generation induced by the plasmonic field of the underlying silver nanoparticles. TiO2 thin films are deposited on supported silver nanoparticles and are separated from each other by a fine-tunable thickness of SiO2 interlayer. The TiO2(15 nm)/SiO2/Ag nanoparticle architectures with systematic variation of SiO2 interlayer thickness of 2, 5, 10, and 20 nm show systematic increase in photocatalytic efficiency with decrease in the SiO2 thickness. The efficiency enhancement is shown to be caused by plasmonically enhanced carrier generation, which was confirmed through photocurrent measurements and Raman spectroscopy. With a 2 nm SiO2 interlayer that exhibited the best photocatalytic performance, a 3 times increase in photocurrent density, and a 200 times increase in Raman signal intensity of TiO2 is found. Atomic layer deposition was employed to achieve precise film thickness control of SiO2 and TiO2...

Atomically Precise Growth of Catalytically Active Cobalt Sulfide on Flat Surfaces and within a Metal-Organic Framework via Atomic Layer Deposition.

Abstract: Atomic layer deposition (ALD) has been employed as a new synthetic route to thin films of cobalt sulfide on silicon and fluorine-doped tin oxide platforms. The self-limiting nature of the stepwise synthesis is established through growth rate studies at different pulse times and temperatures. Additionally, characterization of the materials by X-ray diffraction and X-ray photoelectron spectroscopy indicates that the crystalline phase of these films has the composition Co9S8. The nodes of the metal–organic framework (MOF) NU-1000 were then selectively functionalized with cobalt sulfide via ALD in MOFs (AIM). Spectroscopic techniques confirm uniform deposition of cobalt sulfide throughout the crystallites, with no loss in crystallinity or porosity. The resulting material, CoS-AIM, is catalytically active for selective hydrogenation of m-nitrophenol to m-aminophenol, and outperforms the analogous oxide AIM material (CoO-AIM) as well as an amorphous CoSx reference material. These results reveal AIM to be an eff...

Improvement in Al2O3 dielectric behavior by using ozone as an oxidant for the atomic layer deposition technique

Abstract: We have prepared Al2O3 films by the atomic layer deposition technique using trimethylaluminum as the precursor for aluminum and O3, instead of commonly used H2O, as an oxidant. We show that even without any postdeposition annealing or any preventive layer between the Al2O3 film and Si substrate to suppress the formation of metallic clusters, the Al2O3 films prepared using O3 have significantly less amount of defect states like Al–Al and OH bonds compared with those prepared by H2O. The films show device quality leakage characteristics, with Al2O3 film prepared with O3 showing a leakage current density one or two orders lower and a smaller flatband voltage shift than that of Al2O3 film prepared with H2O, demonstrating improved interface characteristics. The former also shows a very low wet etch rate.

Realization of vertical resistive memory (VRRAM) using cost effective 3D process

Abstract: Vertical ReRAM (VRRAM) has been realized with modification of Vertical NAND (VNAND) process and architecture as a cost-effective and extensible technology for future mass data storage. Dedicated ALD/CVD deposition and wet etching processes were developed to reproduce planar ReRAM properties in VRRAM structure. Multi-stack of VRRAM cell layers were fabricated at the same time using ALD TaOx/barrier layer/CVD TiN cell stacks. Oxidation control without intermixing has been found very critical in the vertical ReRAM cell process.

Atomic layer deposition of metal tellurides and selenides using alkylsilyl compounds of tellurium and selenium.

Abstract: Atomic layer deposition (ALD) of metal selenide and telluride thin films has been limited because of a lack of precursors that would at the same time be safe and exhibit high reactivity as required in ALD Yet there are many important metal selenide and telluride thin film materials whose deposition by ALD might be beneficial, for example, CuInSe2 for solar cells and Ge2Sb2Te5 for phase-change random-access memories Especially in the latter case highly conformal deposition offered by ALD is essential for high storage density By now, ALD of germanium antimony telluride (GST) has been attempted only using plasma-assisted processes owing to the lack of appropriate tellurium precursors In this paper we make a breakthrough in the development of new ALD precursors for tellurium and selenium Compounds with a general formula (R3Si)2Te and (R3Si)2Se react with various metal halides forming the corresponding metal tellurides and selenides As an example, we show that Sb2Te3, GeTe, and GST films can be deposited by ALD using (Et3Si)2Te, SbCl3, and GeCl2 x C4H8O2 compounds as precursors All three precursors exhibit a typical saturative ALD growth behavior and GST films prepared at 90 degrees C show excellent conformality on a high aspect-ratio trench structure