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.

Method for forming a film and method for manufacturing a thin film transistor

Abstract: A crystal silicon film deposited on an insulating film made of a binary system material or a binary system semiconductor film formed by an atomic layer deposition method has a grain as large as approximately 200 nm. Thus, the mobility of carriers is increased. The crystal silicon thereof is grown within a temperature range of 250° C. to 400° C. Accordingly, when a planar type thin film transistor, an inverted stagger type thin film transistor or a stagger type thin film transistor is formed using crystal silicon formed on these films made of a binary system material, transistor characteristics thereof are improved. Further, when an impurity containing silicon film is formed by a chemical vapor deposition method between a source electrode and a drain electrode of a thin film transistor and a silicon film connected to these electrodes, and a flow rate of impurity containing gas is regulated so that impurity density becomes larger as approaching to the source electrode and the drain electrode, a leakage current in an OFF-state of the transistor is reduced. Since the impurity containing silicon film is grown by a chemical vapor deposition method in this case, the impurity density thereof can be controlled easily and the control accuracy is also improved.

Superior Stable and Long Life Sodium Metal Anodes Achieved by Atomic Layer Deposition.

Abstract: Na-metal batteries are considered as the promising alternative candidate for Li-ion battery beneficial from the wide availability and low cost of sodium, high theoretical specific capacity, and high energy density based on the plating/stripping processes and lowest electrochemical potential. For Na-metal batteries, the crucial problem on metallic Na is one of the biggest challenges. Mossy or dendritic growth of Na occurs in the repetitive Na stripping/plating process with an unstable solid electrolyte interphase layer of nonuniform ionic flux, which can not only lead to the low Coulombic efficiency, but also can create short circuit risks, resulting in possible burning or explosion. In this communication, the atomic layer deposition of Al2O3 coating is first demonstrated for the protection of metallic Na anode for Na-metal batteries. By protecting Na foil with ultrathin Al2O3 layer, the dendrites and mossy Na formation have been effectively suppressed and lifetime has been significantly improved. Furthermore, the thickness of protective layer has been further optimized with 25 cycles of Al2O3 layer presenting the best performance over 500 cycles. The novel design of atomic layer deposition protected metal Na anode may bring in new opportunities to the realization of the next-generation high energy-density Na metal batteries.

Synthesis and Stabilization of Supported Metal Catalysts by Atomic Layer Deposition

Abstract: Supported metal nanoparticles are among the most important cata-lysts for many practical reactions, including petroleum refining, automobile exhaust treatment, and Fischer–Tropsch synthesis. The catalytic performance strongly depends on the size, composition, and structure of the metal nanoparticles, as well as the underlying support. Scientists have used conventional synthesis methods including impregnation, ion exchange, and deposition–precipitation to control and tune these factors, to establish structure–performance relationships, and to develop better catalysts. Meanwhile, chemists have improved the stability of metal nanoparticles against sintering by the application of protective layers, such as polymers and oxides that encapsulate the metal particle. This often leads to decreased catalytic activity due to a lack of precise control over the thickness of the protective layer.A promising method of catalyst synthesis is atomic layer deposition (ALD). ALD is a variation on chemical vapor deposition in ...

Methods for making a dielectric stack in an integrated circuit

Abstract: An ultrathin aluminum oxide and lanthanide layers, particularly formed by an atomic layer deposition (ALD) type process, serve as interface layers between two or more materials. The interface layers can prevent oxidation of a substrate and can prevent diffusion of molecules between the materials. In the illustrated embodiments, a high-k dielectric material is sandwiched between two layers of aluminum oxide or lanthanide oxide in the formation of a transistor gate dielectric or a memory cell dielectric. Aluminum oxides can serve as a nucleation layer with less than a full monolayer of aluminum oxide. One monolayer or greater can also serve as a diffusion barrier, protecting the substrate from oxidation and the high-k dielectric from impurity diffusion. Nanolaminates can be formed with multiple alternating interface layers and high-k layers, where intermediate interface layers can break up the crystal structure of the high-k materials and lower leakage levels.

Integrated circuit devices having buffer layers therein which contain metal oxide stabilized by heat treatment under low temperature

Abstract: Integrated circuit devices include a first dielectric layer, an electrically insulating layer on the first dielectric layer and an an aluminum oxide buffer layer formed by atomic layer deposition (ALD) and stabilized by heat treatment at a temperature of less than about 600° C., between the first dielectric layer and the electrically insulating layer. The first dielectric layer may comprise a high dielectric material such as a ferroelectric or paraelectric material. The electrically insulating layer may also comprise a material selected from the group consisting of silicon dioxide, borophosphosilicate glass (BPSG) and phosphosilicate glass (PSG). To provide a preferred integrated circuit capacitor, a substrate may be provided and an interlayer dielectric layer may be provided on the substrate. Here, a metal layer may also be provided between the interlayer dielectric layer and the first dielectric layer. The metal layer may comprise a material selected from the group consisting of Pt, Ru, Ir, and Pd.