Abstract: Defects in reactively sputtered titanium nitride diffusion barriers in submicron devices were investigated. Four different failure mechanisms could be extracted, two originating from the production of the layers, two related to foregoing process steps. The latter are contact hole overetch and topology inside the contact hole, i.e., edges, created by deviating isotropic etch ratios of different dielectric layers in a post‐treatment after the contact etch. The insufficiencies related to the preparation of the TiN films are microcracks due to excessive stress incorporated and encroachment caused by a Ti‐rich titanium nitride on the contact hole walls, proved by an Auger electron spectroscopy analysis. Accidental accumulation of two or more of these defects in a production line can cause the barrier to fail. The process of contact degradation was investigated by transmission electron microscopy and energy‐dispersive x rays. It was found that after aluminum penetration the destruction of the contact area proceeds via a ternary AlxTiySiz reaction until all titanium is consumed, followed by the growth of a pure Al spike and the fatal breakdown of the contact.

Abstract: Reactively sputtered tantalum nitride (Ta2N) has been investigated as a diffusion barrier between Pd2Si and aluminum and CoSi2 and Al. Ta2N is found to be an excellent matallurgical diffusion barrier for the two systems up to 555 °C, with no intermixing observed in Rutherford backscattering and Auger electron spectroscopic studies. Schottky barrier devices n‐Si/Pd2Si/Ta2N/Al were excellent and showed no deterioration after annealing at 500 °C. However, similar devices with CoSi2 contacts and Ta2N barrier showed a creation of high contact resistance between the silicide and the as‐deposited nitride.

Abstract: A coated body consisting of a substrate that can be decarburized during a carbide, nitride or carbonitride coating process comprising a first (innermost) carbon diffusion retarding coating of MetCO, MetCON, MetON adjacent to the substrate and a second (next innermost) wear resistant coating of MetC, MetN and/or MetCN, where Met is Ti, Hf, V, Zr, Si, B or other metals of subgroup 3-7 of the periodic table of the elements, or a mixture thereof. The intermediate coating has been found beneficial in order to reduce or even eliminate the formation of eta phase in the substrate.

Abstract: Disclosed is a Schottky diode having a platinum silicide Schottky anode layer (25) formed in electrical contact with an underlying silicon semiconductor layer (14). A sidewall oxide (36) is formed around the periphery of the platinum silicide area (25) to prevent etching processes from exposing a portion of the underlying silicon semiconductor layer (14). A titanium tungsten diffusion barrier layer (26) and an aluminum composition layer (28) are formed thereover to provide electrical contact to the Schottky diode.

Abstract: Thin films of titanium boride were deposited by reactive sputtering in a mixture of argon and 6% diborane. The use of reactive sputtering makes it possible to deposit films with different compositions. The overall composition of the films was determined by Rutherford backscattering. The crystallization of the films and the variation in resistivity with the annealing temperature have been studied. The minimum resistivity was obtained for stoichiometric TiB2. It was confirmed by both Rutherford backscattering and Auger depth profiling that titanium boride prevents reactions between silicon and aluminum up to temperatures slightly above 600 °C. Structures with TiB2 acting as a diffusion barrier between silicon and aluminum, and a more sophisticated metallization structure also containing a thin titanium layer for silicide formation during heat treatments, have been studied.

Abstract: A diffusion barrier structure includes a first barrier layer provided on a substrate of a semiconductor device for preventing transport of component elements of the substrate and the electrode from passing therethrough by diffusion. An interface layer is formed in the first barrier layer adjacent to a top surface of the first barrier layer for eliminating the effect of microstructure in the first barrier layer on crystal growth to be made on the first barrier layer. A second barrier layer of a same material as the material of the first barrier layer is provided on the first barrier layer so as to be sandwiched between the first barrier layer and the metal electrode for preventing the component elements from being transported therethrough by diffusion.

Abstract: Thin films of tungsten silicide have been formed by sputter depositing 710 A of W metal onto (100)‐oriented, 3–7 Ω cm, p‐type silicon wafers. The samples were annealed in an ultrahigh vacuum ambient (pressure≤1.0×10−9 Torr) at temperatures ranging from 845 to 1100 °C for 30 s. The lack of oxygen contamination in the ambient allows the W‐Si interaction to proceed, first producing both the W‐rich W5 Si3 phase and the tetragonal WSi2 phase near 900 °C, followed by only the tetragonal, low‐resistivity (30–40 μΩ cm) WSi2 phase above 1000 °C. This result is in contrast to previous work where films formed by rapid thermal processing in vacuum showed no significant W‐Si interaction for temperatures below 1100 °C due to the formation of an interfacial oxide diffusion barrier gettered into the films from the 10−6 Torr ambient.

Abstract: The formation of an interfacial AlN layer was observed in an Al/Si3 N4 thin‐film system immediately after electron beam deposition of Al, employing Auger electron spectroscopy, x‐ray diffraction, and transmission electron microscopy. Heat treatments up to 600 °C resulted in growth of this layer. The Si liberated by the direct reaction between Al and Si3 N4 was found to crystallize into small islands of peculiar fractal‐like shape. The AlN layer acted as a diffusion barrier for diffusion of Al into Si3 N4 .

Abstract: An oxidation protection coating for metal substrate surfaces. The coating, according to a preferred embodiment, comprises an initial or first layer of a glass-ceramic, such as a barium aluminosilicate composed chiefly of baria, silica and alumina; or mullite, composed of silica-alumina or, alternatively, baria-silica. Titanium dioxide, nickel oxide or SnO2 can be added. The next layer of the coating is comprised of alumina or silicon carbide. The third or final layer is comprised of a thin layer of silica or a high-silica material, e.g., a silica containing 4% B2 O3. For a thicker third layer, particles of a dark solid, such as boron silicide, ferrous oxide, ferric oxide, nickel oxide, manganese dioxide, carbon or silicon carbide, can be incorporated. The three-layer coating provides high emittance and low catalytic activity for the recombination of oxygen and nitrogen, as well as being a hydrogen diffusion barrier.

Abstract: PURPOSE:To form a metal film whose shape in an uneven part is smooth and whose surface is flat by a method wherein a first metal of a high-melting-point metal is deposited on the surface including a recessed part, titanium is deposited on the first film in such a way that its film thickness does not close the recessed part and a third metal whose melting point is lower than that of titanium is bias-sputtered on the recessed part. CONSTITUTION:A first metal, e.g., a titanium nitride film 4 as a nitride of titanium of a high-melting-point metal, is deposited, as a first-layer metal, i.e., as a diffusion barrier layer between metals, on a recessed part in an insulating layer 2 formed on a semiconductor water 1. Then, in order to prevent an impurity from being generated from the first-layer barrier metal 4, a titanium layer 5 having a gettering effect is deposited in such a way that its thickness does not close a contact hole 3. Then, a metal whose melting point is lower than that of the titanium layer 5 and the barrier metal 4, e.g., an aluminum layer 6, is formed on the titanium layer 5. In order to improve a step coverage even with a large aspect ratio, e.g., a sputtering operation by an RF bias is executed to the semiconductor substrate 1 in a state that the semiconductor substrate 1 is heated in advance at 200 deg.C or lower; then the aluminum layer 6 is deposited.

Abstract: Tungsten films were deposited on Si substrates by the H2 or Si reduction of WF6 under various experimental conditions. The composition and structure of as-deposited samples as well as the interfacial reactions and interdiffusion of elements in annealed samples were characterized by nuclear reaction analyses, sheet resistance measurements, x-ray diffraction technique, and Rutherford backscattering spectroscopy. The amount of oxygen at W–Si interfaces was found to be dependent on the cleaning treatment of the Si surface used before WF6–Si interaction. The interfacial oxygen concentration was less than 1 ⊠ 1014 at./cm2 (detection limit of the nuclear reaction analysis) and (2–7) ⊠ 1016 at./cm2 using an HF cleaning and the RCA treatment, respectively. For W/Si samples, the formation temperature of WSi2 was dependent on the dopant level in the Si substrates and the oxygen concentration at W–Si interfaces. The silicidation reaction occurred at 625 °C in “oxygen free” W/Si structures while for structures containing interfacial oxygen atoms, this reaction occurred above 800 °C. In Al/W/Si structures, the intermetallic compound, WAl12, was formed by annealing at 450 °C for 90 min. Furthermore, the formation of WSi2 was observed in structures annealed at a temperature in the range of 550 °C–600 °C regardless of the oxygen concentration at the W–Si interface. A model to explain the effect of interfacial oxygen atoms on the silicidation reaction and the influence of the Al overlayer on the thermal stability of Al/W/Si structures is proposed and discussed in this paper.

Abstract: In a method of manufacturing a device comprising a film of an oxide superconducting material which comprises an alkaline earth metal, another metal component, copper and oxygen. A superconductor precursor material comprising copper oxide, alkaline earth metal fluoride and another metal or metal oxide, is provided on a substrate in the form of a film. The film is covered with a diffusion barrier against water in accordance with a pattern which is complementary to a desired pattern of superconducting material. Subsequently, the superconducting material is formed in the uncovered portions of the pattern by means of a treatment at an increased temperature in the presence of water and oxygen.

Abstract: Disclosed is an improved thermal ink jet print head with an amorphous diffusion barrier that inhibits corrosion associated with ink. The head has a silicon substrate, a silicon dioxide insulating layer, a tantalum aluminum alloy (TaAl) resistive layer, and two separated gold conductive regions formed over the resistive layer. Ink is drawn into a channel bounded above by an orifice plate and below by the TaAl exposed between the two separated gold regions. The ink is superheated and expelled as fine droplets through the orifice plate. The invention minimizes corrosion by placing a thin corrosion-resistant layer of amorphous metallic alloy over the conductive layer, thereby improving durability of the print head.

Abstract: A thin film resistor and method of making employs tungsten or tungsten titanium alloy as an alectrically conductive diffusion barrier between the nickel chromium resistor and the gold conductor. A solution of cupric sulfate, ammonium hydroxide, glycerol and deionized water is used to remove the unwanted diffusion barrier without damaging the thin film resistor materials, thereby preserving precision resistance values.

Abstract: We report on our investigation of the silicon nitride on hydrogenated amorphous silicon interface by high frequency capacitance-voltage measurements. We show evidence for the existence of a large number of interface states at energies less than or equal to 0.36 eV below the hydrogenated amorphous silicon conduction band. In addition, we demonstrate that the states responsible for the hysteresis in capacitance-voltage characteristics are located in the silicon nitride layer. Finally, we argue that the ability of hydrogenated amorphous silicon to act as hole diffusion barrier is responsible for the observed flat-band voltage shift.

Abstract: The size of a fusible link (22C F ) created from part of a metal layer (22) is controlled by an oxidation performed in a deposition chamber that is also used for depositing a dielectric layer (30) over the fuse structure. The metal layer serves as a diffusion barrier between semiconductor material (14 and 16) and another metal layer (24).

Abstract: Focusing on texture formation in titanium films, the solid state reactions between the aluminium and titanium layers were studied in Al/Ti/Si and Al/TiN/Ti/Si systems. Titanium films with a (0002) texture exhibited better resistance to the solid state reactions between aluminium and titanium than did those with randomly oriented structure. Interposing a TiN layer between the aluminium and titanium layers resulted in an excellent diffusion barrier as high as the melting point of aluminium.

Abstract: The applicability of PdxTa1−x as a diffusion barrier on Si has been investigated. For this purpose PdxTa1−x films of 200‐nm thickness (x ranges from 0 to 1) were deposited on Si(100), and the reaction between overlayer and substrate was studied as a function of temperature. Interaction was found to occur at temperatures increasing with the Ta content. The as‐deposited PdxTa1−x films with 0.2≤x≤0.6 were found to be amorphous. The amorphous phase had a higher reaction temperature than the crystalline one, causing a discontinuous step in the reaction temperature. Rutherford backscattering spectrometry spectra revealed that for the Pd‐rich compositions, first a stoichiometric Pd2Si layer formed underneath a pure Ta layer. At higher temperatures TaSi2 formed at the surface. For Ta‐rich compositions Pd2Si formed first as well; however, the reaction temperature was so high that Pd2Si grains formed in a Si matrix. The defect density of the Ta layer, which remained after outdiffusion of Pd, was investigated using variable energy positron annihilation. The defect concentration is very high, as deduced from the trapped positron fraction. A model is presented that describes the composition dependence of the reaction temperature.The applicability of PdxTa1−x as a diffusion barrier on Si has been investigated. For this purpose PdxTa1−x films of 200‐nm thickness (x ranges from 0 to 1) were deposited on Si(100), and the reaction between overlayer and substrate was studied as a function of temperature. Interaction was found to occur at temperatures increasing with the Ta content. The as‐deposited PdxTa1−x films with 0.2≤x≤0.6 were found to be amorphous. The amorphous phase had a higher reaction temperature than the crystalline one, causing a discontinuous step in the reaction temperature. Rutherford backscattering spectrometry spectra revealed that for the Pd‐rich compositions, first a stoichiometric Pd2Si layer formed underneath a pure Ta layer. At higher temperatures TaSi2 formed at the surface. For Ta‐rich compositions Pd2Si formed first as well; however, the reaction temperature was so high that Pd2Si grains formed in a Si matrix. The defect density of the Ta layer, which remained after outdiffusion of Pd, was investigated using ...

Abstract: By means of conventional deposition and lift-off processes, a metal contact plate is simultaneoulsy placed over transistor junction surfaces and over the surrounding field oxide boundary. After this process step, a dielectric layer, insulating the metal interconnect from the gate interconnect, is deposited and contact openings are plasma etched down to the metal contact plate, which acts to prevent erosion of the junction surface and the field oxide layer. When a diffusion barrier metal is used, the thermal stability of the contact resistance and the electromigration susceptibility are improved. While maintaining minimum transistor design dimensions and required alignment tolerances, the contacting metal plate allows for an increase in the contact opening area.

Abstract: An amorphous Ni–B alloy was formed at the interfaces between layers of polycrystalline nickel and amorphous boron during electron-beam deposition of Ni/B/Ni trilayer structures. Formation of the amorphous alloy appears to be thermally-assisted and, in addition, the amorphous alloy regions can be extended by post-deposition ion-beam mixing. The existence of an upper limit to the thickness of the amorphous Ni–B alloy layer which forms (40 nm) indicates that the amorphous layer serves as a reaction or diffusion barrier. It has been shown for the first time that an amorphous metal-boron alloy is produced by thermal solid state amorphization reaction (SSAR).

Abstract: A method of forming a eutectic bond, of Cadmium Telluride to Sapphire utilizing the Gold/Silicon eutectic bonding of the Cadmium Telluride to the Sapphire. A multi-layer structure of: Chromium which provides adhesion to the Cadmium Telluride; a Titanium layer which functions as a diffusion barrier to the Gold, and a Gold layer are sequentially evaporated on the Cadmium Telluride; a separate multilayered structure of: Silicon grown on Sapphire, and Gold evaporated upon the Silicon. These two multilayered structures are then eutectically bonded. This method enables the expansion coefficient of the eutectic layer to be tailored through the Gold concentration to match that of the Cadmium Telluride. This method also allows the bonding stress to be confined between the Gold/Silicon eutectic and the Sapphire substrate, eliminating the bonding stress in the Cadmium Telluride. Also, due to the precision of the thickness of the evaporated layers, the bonded substrates are inherently planar and parallel.

Abstract: Indium-tin oxide (ITO) thin films were examined as a buffer layer between high-Tc superconducting Y-Ba-Cu-O thin films and glass substrates. It was found that ITO film can become a diffusion barrier between the superconducting film and glass substrate, and that it does not cause any cracks in Y-Ba-Cu-O film if an appropriate silicate glass substrate is chosen. The superconducting film deposited on ITO/Glass below 700°C has shown onset transition temperatures up to 91 K and zero resistivity temperatures at 50 K.

Abstract: On a semiconductor substrate (14, 38) T-type undercut electrical contact structure (12, 36) and methodology provides a diffusion barrier (26, 40) preventing migration therethrough from a gold layer (30, 48) along the sides of an undercut schottky metal lower layer (28, 44) into the active region of the semiconductor substrate. In one embodiment, the diffusion barrier (26) is provided at the base of the gold layer (30). In another embodiment, the gold layer (48) is encapsulated by the diffusion barrier (40) on the bottom (46) and sides (56). The diffusion barrier base layer is deposited. The diffusion barrier side layers are electroplated.

Abstract: TiN is used in advanced integrated circuits as a diffusion barrier between Al metallization and Si substrate. Quantitative analysis of the TiN composition in contact holes of submicron devices is a particular challege for Auger spectroscopy owing to the contact hole geometry and topography (low signal-to-noise ratio, shadowing effects, scattering of primary electrons) and owing to material-related problems (peak overlapping and lineshape changes, preferential sputtering, crystalline effects). It will be shown how methods of sample preparation and data evaluation can be used to advantage in solving these difficulties. The analysis reveals that the sputter-deposited barrier layer is depleted in nitrogen at the contact hole wall.

Abstract: The Interfacial reactions between Al and RuO2, MoOx and WNx diffusion barriers on Si (100) wafers have been studied. The diffusion barrier structures were analyzed before and after various heat treatments using Auger electron spectroscopy (AES) and cross-sectional transmission electron microscopy (XTEM). Al was found to reduce the oxides of both Ru and Mo. A 100 A thick Al2O3 layer developed between the Al and the RuO2 films during annealing at 500°C for 30 minutes. The formation of interfacial Al2O3 efficiently prevents Al penetration but may cause a too high contact resistance for applications in contact structures of microelectronic devices. The WNx barrier was stable after annealing at 600°C for 30 minutes, if the film was exposed to air prior to Al deposition. If, instead, the Al was deposited in situ, the structure failed after annealing at 500°C due to a reaction between Al and W giving WAl12. A thin Al2O3 layer was detected between the Al and the WNx films of the air exposed sample. This layer had the effect of retarding the Al–W reaction and thereby raised the failure temperature of the barrier by at least 100°C.