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.

Self-Directed Localization of ZIF-8 Thin Film Formation by Conversion of ZnO Nanolayers

Abstract: Control of localized metal–organic framework (MOF) thin film formation is a challenge Zeolitic imidazolate frameworks (ZIFs) are an important sub-class of MOFs based on transition metals and imidazolate linkers Continuous coatings of intergrown ZIF crystals require high rates of heterogeneous nucleation In this work, substrates coated with zinc oxide layers are used, obtained by atomic layer deposition (ALD) or by magnetron sputtering, to provide the Zn2+ ions required for nucleation and localized growth of ZIF-8 films ([Zn(mim)2]; Hmim = 2-methylimidazolate) The obtained ZIF-8 films reveal the expected microporosity, as deduced from methanol adsorption studies using an environmentally controlled quartz crystal microbalance (QCM) and comparison with bulk ZIF-8 reference data The concept is transferable to other MOFs, and is applied to the formation of [Al(OH)(1,4-ndc)]n (ndc = naphtalenedicarboxylate) thin films derived from Al2O3 nanolayers

Catalytically enhanced atomic layer deposition process

Abstract: A method for carrying out a damascene process to form an interconnect comprises providing a semiconductor substrate having a trench etched into a dielectric layer, wherein the trench includes a barrier layer and an adhesion layer, depositing a copper seed layer onto the adhesion layer using an ALD process, depositing an iodine catalyst layer onto the copper seed layer using an ALD process, and depositing a copper layer onto the copper seed layer using an ALD process. The iodine catalyst layer causes the copper layer to fill the trench by way of a bottom-up fill mechanism. The trench fill is performed using a single ALD process, which minimizes the creation of voids and seams in the final copper interconnect.

Atomic Layer Deposition of the Solid Electrolyte Garnet Li7La3Zr2O12

Abstract: Lithium solid electrolytes are a promising platform for achieving high energy density, long-lasting, and safe rechargeable batteries, which could have widespread societal impact. In particular, the ceramic oxide garnet Li7La3Zr2O12 (LLZO) has been shown to be a promising electrolyte due to its stability and high ionic conductivity. Two major challenges for commercialization are the manufacture of thin layers and the creation of stable, low-impedance interfaces with both anode and cathode materials. Atomic layer deposition (ALD) has recently been shown to be a powerful method for depositing both solid electrolytes and interfacial layers to improve the stability and performance at electrode–electrolyte interfaces in battery systems. Herein, we present a thermal ALD process for LLZO, demonstrating the ability to tune composition within the amorphous as-deposited film, which is studied using in situ quartz crystal microbalance measurements. Postannealing using a variety of substrates and gas environments was ...

Promoting water photooxidation on transparent WO3 thin films using an alumina overlayer

Abstract: Tungsten trioxide (WO3) is being investigated as one of the most promising materials for water oxidation using solar light. Its inherent surface-related drawbacks (e.g., fast charge recombination caused by surface defect sites, the formation of surface peroxo-species, etc.) are nowadays being progressively overcome by different methods, such as surface passivation and the deposition of co-catalysts. Among them, the role of surface passivation is still poorly understood. Herein, transparent WO3 (electrodeposited) and Al2O3/WO3 (prepared by atomic layer deposition, ALD) thin film electrodes were employed to investigate the role of an alumina overlayer by using both photoelectrochemical and laser flash photolysis measurements. Films with a 5 nm-alumina overlayer (30 ALD cycles) showed an optimum photoelectrochemical performance, portraying a 3-fold photocurrent and Faradaic efficiency enhancement under voltage biases. Moreover, IPCE measurements revealed that alumina effect was only significant with an applied potential ca. 1 V (vs. Ag/AgCl), matching the thermodynamic potential for water oxidation at pH 1 (0.97 V vs. Ag/AgCl). According to the investigation of electron accumulation through optical absorption measurements, the alumina overlayer dominantly decreased the number of electron trapping sites on the WO3 surface, eventually facilitating photoelectron transfer to the external circuit in the presence of a positive bias. In addition, the laser flash photolysis measurements of WO3 and Al2O3/WO3 thin films clearly showed that the electron trapping decreased in the presence of the alumina overlayer whereas the hole trapping relatively increased with alumina, facilitating water photooxidation and rendering a more sluggish recombination process. These results provide a physical insight into the passivation process that could be used as a guideline for further development of efficient photoanodes in artificial photosynthesis.