Abstract: The properties of titanium nitride deposited by atomic layer epitaxy (ALE) using three different deposition processes, i.e., TiI4+NH3, TiCl4+NH3 and TiCl4+Zn+NH3, as a diffusion barrier between cop ...

Abstract: Methods and apparatus for forming word line stacks comprise one, or a combination of the following: a silicon diffusion barrier layer, doped with oxygen or nitrogen, coupled between a bottom silicon layer and a conductor layer; an amorphous silicon diffusion barrier coupled between a polysilicon layer and a conductor layer; a thin nitride layer coupled between a bottom silicon layer and a titanium silicide conductor layer, and a bottom silicon layer coupled to a conductor layer, which comprises C54-titanium silicide. Word line stacks formed by the methods of the invention are used in sub-0.25 micron line width applications and have a lower resistivity and improved thermal stability.

Abstract: With rising operating temperatures of gas turbines, interdiffusion may occur between the structural material of the blades (superalloy) and the corrosion-resistant layer (MCrAlY) leading to premature coating failure. Depositing a diffusion barrier between the base material and the layer is a conceivable means to suppress this diffusion. α-Al 2 O 3 appears to be well suited as a diffusion barrier since it passes through no phase transition at high temperatures and possesses a hcp crystal structure with a very small number of defects. However, chemical vapor deposition of α-Al 2 O 3 is known to be difficult because of preferred whisker formation due to the high contents of Ni and Co in the substrate. In this paper two ways to suppress the growth of whiskers and to deposit smooth α-Al 2 O 3 films on nickel base superalloy substrates are presented. Furthermore, the efficiency of the diffusion barrier was tested by annealing experiments at 1100°C for 100 h. The α-Al 2 O 3 films remained dense and very effective as a diffusion barrier.

Abstract: This work concentrates on the diffusion barrier stability of very thin (10 or 20 nm) α- or β-Ta, TaN, Ta(O) and Ta(N,O) films in the Cu/barrier/Si system. Based on the classical theory of the thin film growth and know how of material transport in thin films, the various Ta-based films were classified according to their density of free short-circuit paths. Using scanning electron microscopy, transmission electron microscopy, glow discharge optical emission spectroscopy and secondary ion mass spectrometry, the 20 nm thin polycrystalline columnar-structured β-Ta films were found to be stable up to 500 °C for 1 h. After 1 h at 600 °C Cu3Si was formed due to short-circuit diffusion of Cu throughout the β-Ta films. The 20 nm thin giant-grained α-Ta films show equivalent performance to the β-Ta films. On the other hand, the 10 nm thin stuffed nanocrystalline face-centered-cubic (fcc) TaN films were able to protect the Si from Cu diffusion up to at least 600 °C/1 h. Ten nm thin amorphous-like Ta(N,O) and Ta(O) fi...

Abstract: A variable temperature scanning tunneling microscope was used to directly observe the thermally induced rotation of a single acetylene molecule between two equivalent orientations on Cu(001) above 68 K. Measurements of the rotation rate as a function of temperature yielded an energy barrier of 169±3 meV and a preexponential factor of 1011.8±0.2 s−1. Thermal diffusion of individual acetylene molecules was monitored above 178 K by single molecule tracking. A diffusion barrier of 0.53±0.01 eV and a preexponential factor of 1013.6±0.2 s−1 were determined by measuring the hopping rate as a function of temperature.

Abstract: Amorphous metal oxide barrier layers of titanium oxide, zirconium oxide and zinc/tin oxide are effective as alkali metal ion barrier layers at thicknesses below 180 Angstroms. The amorphous metal oxide barrier layers are most effective when the density of the layer is equal to or greater than 75 % of the crystalline density. The barrier layers prevent migration of alkali metal ions such as sodium ions from glass substrates into a medium e.g. electrolyte of a photochromic cell, liquid material of a liquid crystal display device contacting the glass surface and a photocatalytic coating. The properties of the medium, particularly electroconductive metal oxide coatings, are susceptible to deterioration by the presence of sodium ions migrating from the glass.

Abstract: A coating for use on a superalloy substrate comprising a diffusion barrier as an intermediate layer overlying the substrate and underlying a protective coating having a high aluminum content. The diffusion barrier layer is characterized by having low solubility for aluminum from either the substrate or the protective coating. Further, the diffusion barrier layer has low interdiffusivity for elements from the substrate and the coating, a minimal impact on the mechanical properties of the article which is coated, a minimal thermal expansion mismatch with both the substrate and the high aluminum content protective coating, and can be applied readily using existing coating application techniques. The diffusion barrier is preferably a single phase alloy or intermetallic compound.

Abstract: A silicon carbon nitride (SiCN) layer is provided which has a low leakage current and is effective in preventing the migration or diffusion of metal or copper atoms through the SiCN layer. The SiCN layer can be used as a diffusion barrier between a metal portion (such as a copper line or via) and an insulating dielectric to prevent metal atom diffusion into the dielectric. The SiCN layer can also be used as an etchstop or passivation layer. The SiCN layer can be applied in a variety ways, including PECVD (e.g., using SiH 4 , CH 4 , and NH 3 ) and HDP CVD (e.g., using SiH 4 , C 2 H 2 , and N 2 )

Abstract: The ferroelectric properties of Pb(Zr,Ti)O3 films are known to degrade when subjected to forming gas anneals. In an earlier publication we established that although there may be loss of oxygen and lead during forming gas anneal, the primary mechanism for loss of ferroelectricity is the incorporation of hydrogen and subsequent formation of [OH]−1 bonds between the ionized hydrogen and oxygen ions along the polarization axis in the octahedra. In this study, we show that (La,Sr)CoO3 oxide electrodes can act as a diffusion barrier to hydrogen during forming gas anneals. Forming gas anneal at lower temperatures such as 200 and 300 °C does not lead to a measurable loss of polarization. There is some loss of polarization during forming gas anneals at 450 °C for 12 h, however the capacitors still exhibit ferroelectric properties. The capacitors show no fatigue up to 1011 cycles, no imprint, good logic state retention characteristics, and similar slopes for the pulse width dependent polarization values before and ...

Abstract: TiN films are used as a diffusion barrier in ultralarge-scale-integrated (ULSI) circuits because of their thermal stability, low resistivity, and good barrier properties for Al diffusion. 1-4 TiN films have been prepared to date mainly by using the sputtering method, but due to the decreased feature size in silicon devices, chemical vapor deposition (CVD) of TiN is required for conformal coverage. Much effort has been devoted toward CVD of TiN using TiCl 4 , but several problems have limited the applications of TiCl 4 in device manufacturing. The deposition temperature in TiCl 4 chemistry is too high for ULSI applications and chlorine incorporation in the film, especially at low deposition temperatures (<5008C), is of major concern due to a corrosion problem. 5 To avoid these problems, metallorganic chemical vapor deposition (MOCVD) with organometallic compounds such as tetrakis(dimethylamido)titanium (TDMAT) and tetrakis(diethylamido)titanium (TDEAT) was introduced and the deposition of TiN using MOCVD has been studied. 6,7 In MOCVD of TiN with ammonia, particle formation and poor conformity were problems as a result of its high gasphase reactivity. To suppress particle formation, a thermal decomposition process using a metallorganic source without ammonia was studied. 8,9 The deposition behavior of TDMAT and TDEAT has been reported earlier, 6,7 but the thermal decomposition mechanism and its effect on the deposition process are still far from being clear. In this paper, we studied the thermal stability and the decomposition mechanism of TDMAT and TDEAT for MOCVD of TiN.

Abstract: Container structures for use in integrated circuits and methods of their manufacture. The container structures include a bottom conductive layer, a top conductive layer and a dielectric layer interposed between the bottom conductive layer and the top conductive layer. The container structures further include a diffusion barrier layer interposed between the dielectric layer and the bottom conductive layer. The diffusion barrier layer acts to inhibit atomic diffusion to at least a portion of the bottom conductive layer, particularly atomic diffusion of oxygen during formation or annealing of the dielectric layer. The container structures are especially adapted for use as container capacitors. The container capacitors are further adapted for use in memory cells and apparatus incorporating such memory cells, as well as other integrated circuits.

Abstract: TaN x films were deposited by chemical vapor deposition using a pentakis(diethylamido)tantalum (PDEAT) source with and without NH 3 at temperatures ranging from 300 to 375°C. It was observed that both the resistivity and carbon content of the film drastically decreased upon the addition of NH 3 . For example, the resistivity decreased from 60,000 to 12,000 μΩ cm, and the apparent carbon content obtained by Auger electron spectroscopy decreased from 30 to 1 atom % by the addition of 25 sccm NH 3 . The grain size initially increased with the addition of 5 sccm NH 3 in the source gas, but then decreased as the NH 3 flow rate was increased to more than 10 sccm. As-deposited TaN x film has a face-centered cubic structure irrespective of the amount of NH 3 . The density of the film increased from about 5.1 to 7.2 g cm -3 (bulk density of TaN: 16.3 g cm -3 ). Barrier failure results identified by the etch-pit test showed that a 50 nm thickness of the TaN x barrier deposited by a single source of PDEAT survived up to 500°C after 1 h annealing. The TaN x film deposited with 25 sccm NH 3 survived up to 550°C after 1 h annealing. However, the step coverage of the films deposited with NH 3 is drastically decreased, from more than 80% (NH 3 = 0 sccm) to less than 10% (NH 3 = 25 sccm). Thus, while the addition of NH 3 significantly improves both the resistivity and carbon content in the film, it deteriorates the step coverage of the film.

Abstract: A metal-organic chemical vapor deposition process has been developed for the growth of amorphous tungsten nitride thin films for barrier layer applications in ultralarge scale integration copper interconnect schemes. The process employs tungsten hexacarbonyl, [W(CO)6] and ammonia (NH3) as, respectively, the tungsten and nitrogen sources. Tungsten nitride films were produced within a wide process window, including a substrate temperature of 200–350 °C, W(CO)6 flow rate of 1–20 sccm, reactor pressure of 0.2–0.5 Torr, and NH3 flow rates of 100–500 sccm. The films were analyzed by x-ray photoelectron spectroscopy, cross-section scanning electron microscopy, x-ray diffraction, transmission electron microscopy, four-point resistivity probe, and Rutherford backscattering spectrometry. These studies indicated that the films consisted predominantly of a W2N phase. Films were grown with carbon and oxygen concentrations ⩽5 at. %, even at the lowest processing temperature investigated, where precursor dissociation wo...

Abstract: An improved CVD process, preferably a PECVD process, for forming a low-dielectric-constant insulating material on a semiconductor substrate, or on and/or under a metal barrier, or etch stop layer of SiNx, Ta(N), TiN, WNx and others. Specifically, the improved PECVD process provides for deposition of an N 2 O+SiF 4 +SiH 4 based FSG film having improved characteristics, which may be accomplished in any conventional PECVD chamber, but preferably in a dual frequency PECVD chamber.

Abstract: The barrier performance and properties (resistivity, crystalline phase and surface microroughness) of tantalum nitride films, as well as the relationship between grain size and diffusivity of copper films, are reported. The resistivity and Ra roughness of Ta2N film formed by reactive sputtering using argon and nitrogen plasma are ~200 µΩcm and ~0.35 nm, respectively. The Ta2N diffusion barrier exhibits better barrier performance than Ta4N and bcc-Ta diffusion barriers. Giant-grain copper interconnects formed by sputtering in low-energy ion bombardment process show lower diffusivity than small-grain copper interconnects. The barrier performance of tantalum nitride film was evaluated by electrical measurement. An n+p junctions having 20 µm×20 µm contact holes filled with 10-nm-thick Ta2N diffusion barriers and giant-grain copper interconnects exhibit no increase in reverse-bias current after annealing at 700°C for 30 min in argon ambient.

Abstract: Using x-ray photoelectron spectroscopy and Rutherford backscattering spectrometry, we have studied structures used in metal–oxide–metal capacitors including Ta2O5/TiN/Ti, Ta2O5/Ti, Ta2O5/TaN/Ti, Ta2O5/WN/Ti, and Ta2O5/M, where M=Ta, Pt, W, Al, and Si. We find that Ti and Al are able to reduce the Ta2O5 to Ta, forming oxides of Ti and Al, respectively. The diffusion barriers TiN, TaN, and WN hamper the diffusion of oxygen and therefore postpone the reduction of Ta2O5 to higher temperatures. As judged by the temperatures at which the reduction of Ta2O5 occurs, TaN and WN are more effective oxygen-diffusion barriers than TiN. We observe no oxygen remaining in the diffusion barrier when a Ti layer is present underneath. We observe no reduction of Ta2O5 when M=Pt, W, or Si.

Abstract: The diffusion barrier properties of three different kinds of chemical vapor deposited (CVD) TiN films were compared against Cu. TiN(A) film (21 nm) was deposited by the thermal decomposition of a single source of tetrakis(dimethylamido)titanium at 400°C. TiN(B) film (19 nm) was prepared by in situ plasma treatment after every 8 nm growth of TiN(A) film. Finally, TiN(C) film (28 nm) was deposited by the reaction of with at 630°C. The densities of TiN(A), TiN(B), and TiN(C) films were 2.55, 4.04, and , respectively. Both TiN(A) and TiN(B) films showed nanocrystalline microstructure with equiaxed grains, the sizes of which were about 4 and 7 nm, respectively. TiN(C) film showed a columnar grain structure with an average grain size of about 14 nm. Sheet resistance measurements, X‐ray diffractometry analyses, and etch‐pit test results consistently demonstrated that the barrier performances of TiN(A) and TiN(B) were superior to those of TiN(C). The diffusion barrier properties of CVD TiN films were discussed in view of the density and microstructure of the film. © 1999 The Electrochemical Society. All rights reserved.

Abstract: A coating is described for use on a superalloy substrate comprising a diffusion barrier as an intermediate layer overlying the substrate and underlying a protective coating having a high aluminum content. The diffusion barrier layer is characterized by having low interdiffusivity for elements from the substrate and the coating, a minimal impact on the mechanical properties of the article which is coated, and can be achieved readily using existing coating application techniques or post heat treat processes. The diffusion barrier layer is preferably an oxide ceramic.

Abstract: The use of copper interconnects enables higher speed, enhanced electromigration lifetime reliability, reduced power consumption, and ultimately reduced manufacturing cost for silicon integrated circuits. The formation of planarized inlaid copper interconnects requires sequential deposition of a continuous diffusion barrier layer followed by copper seed/fill deposition and chemical-mechanical polishing (CMP). In this article we present a vacuum-integrated cluster tool technology for deposition of a TaN barrier and copper seed/fill layers using metalorganic chemical vapor deposition (MOCVD). The MOCVD-based TaN layers deposited at substrate temperatures below 430 °C are highly conformal, have 800–1000 μΩ cm resistivity, have satisfactory adhesion to silicon dioxide, and provide superior diffusion barrier properties compared to Ta and TaN layers deposited by physical vapor deposition. The cluster MOCVD-Cu process is capable of depositing conformal and low-resistivity copper seed layers with satisfactory adhe...

Abstract: A method for use in the fabrication of integrated circuits includes providing a substrate assembly (11) having a surface (12). A diffusion barrier layer (13) is formed over at least a portion of the surface (12). The diffusion barrier layer (13) is formed of RuSix, where x is in the range of about 0.01 to about 10. The barrier layer may be formed by depositing RuSix by chemical vapor deposition or the barrier layer may be formed by forming a layer of ruthenium relative to a silicon containing region and performing an anneal to form RuSix from the layer of ruthenium and the silicon containing region. Capacitor electrodes, interconnects or other structures may be formed with such a diffusion barrier layer.

Abstract: A protective layer in a ferroelectric integrated circuit contains small amounts of oxygen to protect ferroelectric oxide material against hydrogen degradation during the fabrication process. Typically, the protective layer is a hydrogen diffusion barrier layer formed to cover a thin film of ferroelectric oxide material. In one method, a small amount of oxygen is included in the sputter atmosphere during deposition of a hydrogen diffusion barrier or a metallized wiring layer. The oxygen forms oxides that inhibit diffusion of hydrogen towards the ferroelectric oxide material. The oxygen forms a concentration gradient so that the oxygen concentration in the interior of the protective layer is zero, and the oxygen concentration near the surfaces of the layer is about two weight percent.

Abstract: Resumen en: The reactions in the Si/Ta/Cu metallization system produced by a sputtering process were investigated by means of sheet resistance measurements, XRD, RBS...