Showing papers on "Atomic layer deposition published in 2002"

Viscous flow reactor with quartz crystal microbalance for thin film growth by atomic layer deposition

Abstract: A chemical reactor was constructed for growing thin films using atomic layer deposition (ALD) techniques. This reactor utilizes a viscous flow of inert carrier gas to transport the reactants to the sample substrates and to sweep the unused reactants and reaction products out of the reaction zone. A gas pulse switching method is employed for introducing the reactants. An in situ quartz crystal microbalance (QCM) in the reaction zone is used for monitoring the ALD film growth. By modifying a commercially available QCM housing and using polished QCM sensors, quantitative thickness measurements of the thin films grown by ALD are obtained in real time. The QCM is employed to characterize the performance of the viscous flow reactor during Al2O3 ALD.

Atomic Layer Deposition of Hafnium and Zirconium Oxides Using Metal Amide Precursors

Abstract: Atomic layer deposition (ALD) of smooth and highly conformal films of hafnium and zirconium oxides was studied using six metal alkylamide precursors for hafnium and zirconium. Water was used as an oxygen source during these experiments. As deposited, these films exhibited a smooth surface with a measured roughness equivalent to that of the substrate on which they were deposited. These films also exhibited a very high degree of conformality: 100% step coverage on holes with aspect ratios greater than 35. The films were completely uniform in thickness and composition over the length of the deposition reactor. The films were free of detectable impurities and had the expected (2:1) oxygen-to-metal ratio. Films were deposited at substrate temperatures from 50 to 500 °C from precursors that were vaporized at temperatures from 40 to 140 °C. The precursors were found to be highly reactive with hydroxylated surfaces. Their vapor pressures were measured over a wide temperature range. Deposition reactor design and ...

Gas delivery apparatus for atomic layer deposition

Abstract: An apparatus and method for performing a cyclical layer deposition process, such as atomic layer deposition is provided. In one aspect, the apparatus includes a substrate support having a substrate receiving surface, and a chamber lid comprising a tapered passageway extending from a central portion of the chamber lid and a bottom surface extending from the passageway to a peripheral portion of the chamber lid, the bottom surface shaped and sized to substantially cover the substrate receiving surface. The apparatus also includes one or more valves coupled to the gradually expanding channel, and one or more gas sources coupled to each valve.

Atomic layer deposition

Abstract: Publisher Summary This chapter deals with atomic layer deposition (ALD), which is a chemical gas phase thin film deposition method based on alternate saturative surface reactions. As distinct from the other chemical-vapor-deposition techniques, in ALD the source vapors are pulsed into the reactor alternately—one at a time—separated by purging or evacuation periods. Each precursor exposure step saturates the surface with a monomolecular layer of that precursor. This results in a unique self-limiting film-growth mechanism with a number of advantageous features—such as excellent conformality and uniformity and simple and accurate film-thickness control. As the current interest in ALD is largely centered on non-epitaxial films, the chapter focuses on these materials and the related chemistry. ALD is a unique process based on alternate surface reactions, which are accomplished by dosing the gaseous precursors on the substrate alternately. Under ideal conditions, these reactions are saturative, ensuring many advantageous features, such as excellent conformity, large-area uniformity, accurate and simple film-thickness control, repeatability, and large-batch processing capability.

Incorporation of nitrogen into high k dielectric film

Abstract: A high k dielectric film and methods for forming the same are disclosed. The high k material includes two peaks of impurity concentration, particularly nitrogen, such as at a lower interface and upper interface, making the layer particularly suitable for transistor gate dielectric applications. The methods of formation include low temperature processes, particularly CVD using a remote plasma generator and atomic layer deposition using selective incorporation of nitrogen in the cyclic process. Advantageously, nitrogen levels are tailored during the deposition process and temperatures are low enough to avoid interdiffusion and allow maintenance of the desired impurity profile.

Rapid Vapor Deposition of Highly Conformal Silica Nanolaminates

Abstract: Highly uniform and conformal coatings can be made by the alternating exposures of a surface to vapors of two reactants, in a process commonly called atomic layer deposition (ALD). The application of ALD has, however, been limited because of slow deposition rates, with a theoretical maximum of one monolayer per cycle. We show that alternating exposure of a surface to vapors of trimethylaluminum and tris(tert-butoxy)silanol deposits highly conformal layers of amorphous silicon dioxide and aluminum oxide nanolaminates at rates of 12 nanometers (more than 32 monolayers) per cycle. This process allows for the uniform lining or filling of long, narrow holes. We propose that these ALD layers grow by a previously unknown catalytic mechanism that also operates during the rapid ALD of many other metal silicates. This process should allow improved production of many devices, such as trench insulation between transistors in microelectronics, planar waveguides, microelectromechanical structures, multilayer optical filters, and protective layers against diffusion, oxidation, or corrosion.

Atomic layer-deposited laaio3 films for gate dielectrics

Abstract: A dielectric film containing LaAlO 3 and method of fabricating a dielectric film contained LaAlO 3 produce a reliable gate dielectric having a thinner equivalent oxide thickness than attainable using SiO 2 . The LaAlO 3 gate dielectrics formed are thermodynamically stable such that these gate dielectrics will have minimal reactions with a silicon substrate or other structures during processing. A LaAlO 3 gate dielectric is formed by atomic layer deposition employing a lanthanum sequence and an aluminum sequence. A lanthanum sequence uses La(thd) 3 (thd=2,2,6,6-tetramethl-3,5-heptanedione) and ozone. An aluminum sequence uses either trimethylaluminium, Al(CH 3 ) 3 , or DMEAA, an adduct of alane (AlH 3 ) and dimethylehtylamine [N(CH 3 ) 2 (C 2 H 5 )], with distilled water vapor.

Continuous method for depositing a film by modulated ion-induced atomic layer deposition (MII-ALD)

Abstract: The present invention relates to an enhanced sequential atomic layer deposition (ALD) technique suitable for deposition of barrier layers, adhesion layers, seed layers, low dielectric constant (low-k) films, high dielectric constant (high-k) films, and other conductive, semi-conductive, and non-conductive films. This is accomplished by 1) providing a non-thermal or non-pyrolytic means of triggering the deposition reaction; 2) providing a means of depositing a purer film of higher density at lower temperatures; and, 3) providing a faster and more efficient means of modulating the deposition sequence and hence the overall process rate resulting in an improved deposition method.

Utilizing atomic layer deposition for programmable device

Abstract: In an aspect, an apparatus is provided that sets and reprograms the state of programmable devices. In an aspect, a method is provided such that an opening is formed through a dielectric exposing a contact, the contact formed on a substrate. An electrode is conformally deposited on a wall of the dielectric, utilizing atomic layer deposition (ALD). A programmable material is formed on the electrode and a conductor is formed to the programmable material. In an aspect, a barrier is conformally deposited utilizing ALD, between the electrode and the programmable material.

Thermal stability and structural characteristics of HfO2 films on Si (100) grown by atomic-layer deposition

Abstract: The thermal stability and structural characteristics for gate stack structure of HfO2 dielectrics deposited by atomic-layer deposition (ALD) were investigated. The structural characteristics and chemical state of the HfO2 films in relation to the film thickness and postannealing temperature were examined by x-ray diffraction and x-ray photoelectron spectroscopy. An interfacial layer of hafnium silicate with an amorphous structure was grown on the oxidized Si substrate at an initial growth stage. The structural characteristics of the HfO2 films are closely affected by the interfacial layer and are depended on the thickness of the films. The 45 A thick HfO2 film with an amorphous structure was changed into a polycrystalline structure after rapid temperature annealing of 750 °C for 5 min, while thicker films were grown into a polycrystalline structure of monoclinic or tetragonal crystal structure. The silicate layer grown at the interfacial region is not stable even at 700 °C under ultrahigh vacuum condition...

Apparatus and method to achieve continuous interface and ultrathin film during atomic layer deposition

Abstract: A method and apparatus for performing atomic layer deposition in which a surface of a substrate is pretreated to make the surface of the substrate reactive for performing atomic layer deposition.

Method of forming a multilayer dielectric stack

Abstract: A multilayer dielectric stack is provided which has alternating layers of a high-k material and an interposing material. The presence of the interposing material and the thinness of the high-k material layers reduces or eliminate effects of crystallization within the high-k material, even at relatively high annealing temperatures. The high-k dielectric layers are a metal oxide of preferably zirconium or hafnium. The interposing layers are preferably amorphous aluminum oxide, aluminum nitride, or silicon nitride. Because the layers reduce the effects of crystalline structures within individual layers, the overall tunneling current is reduced. Also provided are atomic layer deposition, sputtering, and evaporation as methods of depositing desired materials for forming the above-mentioned multilayer dielectric stack.

Method of growing electrical conductors

Abstract: A method for forming a conductive thin film includes depositing a metal oxide thin film on a substrate by an atomic layer deposition (ALD) process. The method further includes at least partially reducing the metal oxide thin film by exposing the metal oxide thin film to a reducing agent, thereby forming a seed layer. In one arrangement, the reducing agent comprises one or more organic compounds that contain at least one functional group selected from the group consisting of —OH, —CHO, and —COOH. In another arrangement, the reducing agent comprises an electric current.

Passivation method for improved uniformity and repeatability for atomic layer deposition and chemical vapor deposition

Abstract: A method to deposit a passivating layer of a first material on an interior reactor surface of a cold or warm wall reactor, in which the first material is non-reactive with one or more precursors used to form a second material. Subsequently when a film layer is deposited on a substrate by subjecting the substrate to the one or more precursors, in which at least one precursor has a low vapor pressure, uniformity and repeatability is improved by the passivation layer.

Deposition methods and apparatus for improved delivery of metastable species

Abstract: The invention includes a deposition system having a reservoir for containment of a metastable specie connected to a deposition chamber. The system includes a metastable specie generating catalyst within the reservoir. The invention also includes an atomic layer deposition apparatus having a deposition chamber that contains a substrate platform, first and second inlets and a dispersion head positioned between the inlets and the substrate platform. The ALD apparatus includes first and second metastable specie containment reservoirs in fluid communication with the deposition chamber through the inlets. One or more sources of carrier gas are configured to deliver carrier gas through at least one of the inlets. The invention also includes an atomic layer deposition method.

Properties of hafnium oxide films grown by atomic layer deposition from hafnium tetraiodide and oxygen

Abstract: Polycrystalline monoclinic HfO2 films were atomic layer deposited on Si(100) substrates by a nonhydrous carbon-free process of HfI4 and O2. The oxygen to hafnium ratio corresponded to the stoichiometric dioxide within the limits of accuracy of ion beam analysis. A 1.5–2.0 nm thick SiO2 interface layer formed between the HfO2 films and Si substrates. Hysteresis of the capacitance–voltage curves was observed in Al/HfO2/p-Si(100) structures with oxide grown in the substrate temperature range of 570–755 °C. The hysteresis ceased with an increase in O2 pressure. The effective permittivity of the dielectric layers varied between 12 and 16. The breakdown voltages were found to be lower in the case of higher oxygen doses and higher HfO2 deposition temperatures.

Atomic layer-deposited hafnium aluminum oxide

Abstract: A dielectric film containing HfAlO3 and a method of fabricating such a dielectric film produce a reliable gate dielectric having an equivalent oxide thickness thinner than attainable using SiO2. A gate dielectric is formed by atomic layer deposition employing a hafnium sequence and an aluminum sequence. The hafnium sequence uses HfCl4 and water vapor. The aluminum sequence uses either trimethylaluminum, Al(CH3)3, or DMEAA, an adduct of alane (AlH3) and dimethylethylamine [N(CH3)2(C2H5)], with distilled water vapor. These gate dielectrics containing a HfAlO3 film are thermodynamically stable such that the HfAlO3 film will have minimal reactions with a silicon substrate or other structures during processing.

Massively parallel atomic layer deposition/chemical vapor deposition system

Abstract: A method and apparatus for the use of individual vertically stacked ALD or CVD reactors. Individual reactors are independently operable and maintainable. The gas inlet and output are vertically configured with respect to the reactor chamber for generally axi-symmetric process control. The chamber design is modular in which cover and base plates forming the reactor have improved flow design.

Atomic Layer Deposition of Hafnium Dioxide Films from Hafnium Tetrakis(ethylmethylamide) and Water

Abstract: HfO 2 films were produced from Hf[N(CH 3 )(C 2 H 5 )] 4 and H 2 O, on borosilicate glass, indium-tin-oxide (ITO), and Si(100) substrates, in the temperature range 150-325 °C, using atomic layer deposition (ALD). In the temperature range 200-250 °C, the growth rate of the HfO 2 films was 0.09 nm per cycle, but increased with both increasing and decreasing temperatures. The self-limiting adsorption of Hf[N(CH 3 )(C 2 H 5 )] 4 at 250 °C was verified. The films were stoichiometric dioxides with an O/Hf ratio of 2.0 ± 0.1. The concentrations of residual carbon, nitrogen, and hydrogen, determined using ion beam analysis, were 0.3-0.6 at.-%, 0.1-0.2 at.-%, and 2-3 at.-%, respectively. The films crystallized at growth temperatures exceeding 150-175 °C, and consisted mainly of the monoclinic HfO 2 phase. The refractive index of the films varied between 2.08 and 2.10. The effective permittivities of the HfO 2 films grown in the temperature range 200-300°C varied between 11 and 14.

Band alignments in metal–oxide–silicon structures with atomic-layer deposited Al2O3 and ZrO2

Abstract: The energy barrier height Φ for electrons at the interfaces of various metals (Mg,Al,Ni,Cu,Au) with nanometer-thin Al2O3 and ZrO2 layers grown on (100)Si by atomic layer deposition has been directly measured using internal photoemission of electrons into the insulator. The behavior of the metal/Al2O3 contacts with increasing metal electronegativity XM resembles that of the metal/SiO2 interfaces with ideality factor dΦ/dXM≈1. The metal/ZrO2 contacts exhibit a less ideal behavior with dΦ/dXM≈0.75. The metal–silicon work function differences in structures with Al2O3 and ZrO2 insulators appear to be considerably larger than in the structures with thermally grown SiO2, suggesting the presence of a negative dipole layer at the metal/deposited oxide interface.

Metal nitride formation

Abstract: A process for treating refractory metal-boron layers deposited by atomic layer deposition resulting in the formation of a ternary amorphous refractory metal-nitrogen-boron film is disclosed. The resulting ternary film remains amorphous following thermal annealing at temperatures up to 800° C. The ternary films are formed following thermal annealing in a reactive nitrogen-containing gas. Subsequent processing does not disrupt the amorphous character of the ternary film. arrangement where a blended solution is supplied to a remote point of use.

Quantum chemical study of the mechanism of aluminum oxide atomic layer deposition

Abstract: The atomic layer deposition of alumina using water and trimethylaluminum is investigated using the density functional theory. The atomistic mechanisms of the two deposition half-cycles on Al–CH3* and Al–OH* surface sites are investigated. Both half-cycle reactions proceed through the formation of an Al–O Lewis acid-base complex followed by CH4 formation. The Al–O complexes are relatively stable, with formation energies between 0.57 and 0.74 eV. The CH4 formation activation energies range from 0.52 to 0.91 eV and both half-cycle reactions are exothermic with overall enthalpies of reaction between 1.30 and 1.70 eV.

Apparatus and process of improving atomic layer deposition chamber performance

Abstract: An apparatus and process for atomic layer deposition that minimizes mixing of the chemicals and reactive gases is disclosed. The first precursor and second precursor are only mixed with other chemicals and reactive gases when and where desired by installing and monitoring a dispensing fore-line. Also, independent and dedicated chamber outlets, isolation valves, exhaust fore-lines, and exhaust pumps are provided that are activated for the specific gas when needed.

Chemical vapor deposition methods, atomic layer deposition methods, and valve assemblies for use with a reactive precursor in semiconductor processing

Abstract: The invention includes chemical vapor deposition methods, including atomic layer deposition, and valve assemblies for use with a reactive precursor in semiconductor processing. In one implementation, a chemical vapor deposition method includes positioning a semiconductor substrate within a chemical vapor deposition chamber. A first deposition precursor is fed to a remote plasma generation chamber positioned upstream of the deposition chamber, and a plasma is generated therefrom within the remote chamber and effective to form a first active deposition precursor species. The first species is flowed to the deposition chamber. During the flowing, flow of at least some of the first species is diverted from entering the deposition chamber while feeding and maintaining plasma generation of the first deposition precursor within the remote chamber. At some point, diverting is ceased while feeding and maintaining plasma generation of the first deposition precursor within the remote chamber. Other aspects and implementations are contemplated.

Method of forming a barrier film and method of forming wiring structure and electrodes of semiconductor device having a barrier film

Abstract: There is provided a method of forming a barrier metal which is designed to be interposed between a metal layer and an insulating layer, both constituting a multi-layered structure of semiconductor device, the method comprising the steps of positioning a substrate having the insulating layer formed thereon at a predetermined position inside a processing vessel forming a processing space, and alternately introducing a gas containing a refractory metallic atom, a gas containing Si atom and a gas containing N atom into the processing vessel under a predetermined processing pressure, thereby allowing a refractory metal nitride or a refractory metal silicon nitride to be deposited on the insulating layer by way of atomic layer deposition.