Abstract: A protective diffusion barrier for metalized mirror structures is provided by a layer or coating of silicon nitride which is a very dense, transparent, dielectric material that is impervious to water, alkali, and other impurities and corrosive substances that typically attack the metal layers of mirrors and cause degradation of the mirrors' reflectivity The silicon nitride layer can be deposited on the substrate before metal deposition thereon to stabilize the metal/substrate interface, and it can be deposited over the metal to encapsulate it and protect the metal from corrosion or other degradation Mirrors coated with silicon nitride according to this invention can also be used as front surface mirrors Also, the silver or other reflective metal layer on mirrors comprising thin, lightweight, flexible substrates of metal or polymer sheets coated with glassy layers can be protected with silicon nitride according to this invention

Abstract: The usefulness of reactively sputtered TiN as a diffusion barrier in the AlTiN/Ti/Si metallization scheme in very large scale integration was reported in a previous publication. Two types of TiN thin films were studied in these experiments. Depending on the applied substrate bias voltage, the resulting TiN films can have different properties. Under no‐bias conditions, dark brown colored films (called B films) with low density (3.22 g/cm3), high electrical resistivity (∼400 μΩ cm), and 5%–8% O2 are obtained. A+ ‐75 V dc substrate bias, bright golden colored films (called G films) with high density (∼5.0 g/cm3), low resistivity (∼20 μΩ cm), and negligible O2 are obtained. Even though the B films contain more O2, the G films were found to be better diffusion barriers for silicon. To investigate the effect of film microstructure on the diffusion barriers, cross‐sectional and planar transmission electron microscopy samples were used. Both, brown and golden, types of films have columnar grain structure with app...

Abstract: A semiconductor device, device metallization, and method are described. The device metallization, which is especially designed for submicron contact openings, includes titanium silicide to provide a low resistance contact to a device region, titanium nitride and sputtered tungsten to provide a diffusion barrier, etched back chemical vapor deposited tungsten for planarization, and aluminum or an aluminum alloy for interconnection.

Abstract: WSix thin films on GaAs substrates have been investigated for potential use as refractory gates for self‐aligned metal–semiconductor field‐effect transistor (MESFET) devices. Films with Si/W ratio in the range of 0.19 to 1.76 have been dc magnetron cosputtered. The deposition parameters were optimized to produce adherent films with low stress and minimal impurity content. In order to serve as a refractory gate, the WSix film should perform as a diffusion barrier. The WSi0.45 films satisfied this requirement by having the highest crystallization temperature of 875 °C. Such films remained amorphous following the high‐temperature dopant activation annealing (800 °C), thus reducing Ga and As outdiffusion and preventing pit formation in GaAs under the gate. I–V and C–V measurements were used to characterize contact electrical properties such as barrier height, ideality factor, and carrier concentration. A simulated threshold voltage shift for MESFET structure was obtained by modeling diode results. The WSi0.45...

Abstract: The invention relates to a process for the manufacture of multi-layered wear-resistant CVD- or PVD-coatings applied to hardmetal parts containing WC-Co or WC-Ni, where at least one of the layers is a metal-boronitride layer. According to the invention, the boron concentration in the metal-boronitride layer is maintained below the critical level above which in addition a homogeneous boronitride mixed crystal phase a further phase, particularly a diboride phase is formed. A non-boronic, or only slightly boronic, intermediate layer is employed as a diffusion barrier between the hardmetal and the metal-boronitride layer to limit or prevent the formation of brittle tungsten cobalt boron or tungsten nickel boron phases on the external surface of the hardmetal. The metallic boronitride layer can be applied either as a single layer or in multiple layers alternating with other mechanically resistant layers. The hardmetal part is particularly a cutting insert for machining.

Abstract: To improve the planarization and reliability of low-impedance aluminum metallizations, a substrate provided with a titanium/titanium nitride double layer diffusion barrier layer and having a contact hole is provided or, respectively, filled with an aluminum/silicon alloy sandwich structure composed of a sequence of n aluminum/silicon layers having n-1 intermediate layers of titanium applied thereon, whereby the layer thickness ratio of the titanium intermediate layers to the overall layer thickness d of the metallization behaves like 1:10. The multisandwich metallization manufactured in this way is used in VLSI circuits and, given the same specific resistance achieves a life expectancy that is 10 through 100 times higher than that of the aluminum/silicon/titanium alloys that are otherwise standard.

Abstract: Molybdenum oxide (Mo1-x O x ) and ruthenium oxide (RuO2) films were prepared by rf reactive sputtering of Mo or Ru targets in an O2/Ar plasma. Both films exhibit metallic conductivities. The influence of the deposition parameters on the phase that forms and on the microstructure of Mo1-x O x and RuO2 films is reported. A phase transformation is observed in Mo1-x O x films subjected to heat treatment. The diffusion barrier performance of Mo1-x O x and RuO2 layers interposed between Al and Si is compared.

Abstract: Group III-V compound MISFETs include a low-doped diffusion barrier layer disposed between a source/drain contact-facilitating layer and the channel layer.

Abstract: Known power semiconductor elements for high current carrying capacity (permissible current loading, ampacity) have a contact layer structure of the semiconductor body which does not meet the requirement of solderable and/or pressure-bondable, mechanically stable and satisfactorily adhering contact electrodes. The metallisation, consisting of at least four sublayers, for a semiconductor body having a large active area according to the invention ensures the bonding quality required, especially for large contact areas. The metallisation consists of a first layer made of aluminium, a second layer made of chromium or titanium as an adhesive layer and as a diffusion barrier for the aluminium, a solderable third layer made of nickel, and a final protective layer made of gold or palladium or alternatively of a solderable layer containing one sublayer each made of nickel and copper, copper at the same time being the outermost layer or possibly further being covered with gold or palladium. Use in components and assemblies of high current carrying capacity in power electronics.

Abstract: High reflectivity of aluminum alloy layers causes degradation to occur in photoresist images through reflective light scattering. Titanium nitride used normally as a diffusion barrier under aluminum silicon contacts, can also be applied as an efficient antireflection layer on top of AlSi. Processing advantages over other antireflective layers (ARL) such as hillock suppression and enhanced electromigration resistance are also discussed. Process flow parameters from ARL deposition to wire attach are reviewed as applied to megabit dynamic random access memory development.

Abstract: A series of Nb/Al multilayered samples made by a sputter‐deposition or a cold‐rolling technique was used to simulate reactions in powder metallurgy processed Nb/Al superconducting wires. The sequence of phase formation observed in the Nb/Al multilayered samples was explained using knowledge about the crystal structure of each compound. Three different controlling mechanisms were proposed: the activation energy for nucleation, the energy barrier associated with short range order, and the diffusion barrier by the previously formed phase layer.

Abstract: A single plate capacitor includes a dielectric substrate having high dielectric constant, a first SiO 2 film formed ona lower main surface of the dielectric substrate, a first TiW film formed on the first SiO 2 film, a solder diffusion barrier film of Pt, Pd or Ni formed on the first TiW film, a first Au film formed on the solder diffusion barrier film, a second SiO 2 film formed on an upper main surface of the dielectric substrate, a second TiW formed on the second SiO 2 film and a second Au film formed on the second SiO 2 film

Abstract: Indium oxide (In2O3) films were prepared by reactive rf sputtering of an In target in O2/Ar plasma. We have investigated the application of these films as diffusion barriers in Si/In2O3/Al and Si/TiSi2.3/In2O3/Al metallizations. Scanning transmission electron microscopy together with energy dispersive analysis of x ray of cross-sectional Si/In2O3/Al specimens, and electrical measurements on shallow n + -p junction diodes were used to evaluate the diffusion barrier capability of In2O3 films. We find that 100-nm-thick In2O3 layers prevent the intermixing between Al and Si in Si/In2O3/Al contacts up to 650°C for 30 min, which makes this material one of the best thin-film diffusion barriers on record between Al and Si. (The Si-Al eutectic temperature is 577°C, Al melts at 660°C.) When a contacting layer of titanium silicide is incorporated to form a Si/TiSi2.3/In2O3/Al metallization structure, the thermal stability of the contact drops to 600°C for 30 min heat treatment.

Abstract: Nitridation of TiSi2 has been shown to provide a self‐aligned diffusion barrier layer on top of the silicide. A detailed analysis of the nitridation mechanism shows that the compound formed is TiN as commonly expected. The reaction TiSi2→TiN starts at the surface and progresses through the silicide film with a laterally uniform interface. The Si atoms that are dissociated from the TiSi2 grow epitaxially onto the Si substrate material. Implications for contact applications are mentioned.

Abstract: A process is disclosed for fabricating a metal aluminide composite which comprises providing a metal aluminide, such as titanium aluminide, or a titanium aluminide alloy, and a reinforcing fiber material, such as silicon carbide fiber, and placing an interlayer or diffusion barrier layer in the form of a metal selected from the group consisting of silver, copper and gold, and alloys thereof, between the metal aluminide and the reinforcing fiber material. The interlayer metal can be a foil of the metal or in the form of a coating, such as a silver coating, on the reinforcing fiber material. The metal aluminide, the reinforcing fiber material, and the metal interlayer, e.g., in the form of a packet of a plurality of alternate layers of metal aluminide alloy and reinforcing fiber material, each layer being separated by the metal interlayer, is pressed and heated at an elevated temperature, e.g., ranging from about 900° to about 1200° C., at which diffusion bonding occurs. The diffusion barrier metal, e.g., silver, dissolves in the metal aluminide during consolidation of the metal aluminide matrix with the reinforcing fiber material. A layer of tantalum on silver can be employed as a second diffusion barrier layer, and a third layer, such as titanium alloy, can be applied over the tantalum layer, for increased effectiveness of the diffusion barrier, and preventing crack initiation.

Abstract: The Fe-Mn-Al-based alloys have attracted considerable interest for their potential application in stainless steel usage In this study the oxidation and nitridation behaviour of Fe-31 Mn-9Al-6Cr-086C (wt%) alloy is investigated The effects of a gaseous atmosphere, a pre-existing oxide layer and the alloy phase distribution in the matrix are evaluated with respect to the morphological development and kinetics The nitridation behaviour of the alloy in air is sensitive to the alloy surface condition, such as the alloy phases in the matrix and the oxides in the scale For the aged multiphase alloy, oxidation occurs in the ferrite phase and nitridation takes place in the austenite phase due to the higher solubility of nitrogen The existing interphase boundaries provide an easy path for nitrogen migration and thus promote the nitridation However, the surface oxide layers act as a diffusion barrier for nitrogen The effectiveness of the barrier in the retardation of nitridation depends on the amounts of MnAl2O4 and α-Al2O3 in the oxide layer

Abstract: of the Disclosure MULTILAYER CONTACT STRUCTURE A method for forming a contact structure on a silicon surface comprises forming a TiSi2 layer in intimate contact with the silicon surface and a TiNxOy layer overlying the TiSi2 layer, and forming an Al alloy layer on the TiNxOy layer. The TiSi2 layer provides a good electrical contact to the silicon surface, the Al alloy layer reduces the contact resistance, and the TiNxOy layer provides a diffusion barrier to prevent interaction of the Al alloy and TiSi2 which could degrade the contact. -i-

Abstract: Ceramic thin films were deposited on hot-pressed silicon nitride and silicon carbide substrates to provide corrosion protection to the underlying material High-purity silicon nitride, silicon carbide, and silicon oxynitride (SiO{sub 2}/Si{sub 3}N{sub 4} composite) coatings were deposited by plasma-enhanced chemical vapor deposition and rf sputtering to form an effective diffusion barrier for cation migration into the silica corrosion product Preliminary results indicated that the extent of corrosion in Na{sub 2}SO{sub 4} melts at T = 900{degree}, 950{degree}, and 1,000{degree}C was dependent on the outward diffusion of cations in the grain-boundary phase and the crystallinity of the grain-boundary phase in the uncoated ceramics Accelerated corrosion occurred in these ceramics because of breakdown of the protective silica film formed on the surface Corrosion rates in Na{sub 2}SO{sub 4} melts were reduced by separating the oxide grain-boundary phases from the corrosion products with high-purity covalent ceramic coatings

Abstract: On a semiconductor substrate (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 with the remaining portions of the contact structure being masked by selective oxidation.

Abstract: Barrier layers have been used on top of Ni-Au-Ge alloyed and Pd-Ge ``non-alloyed'' ohmic contacts for GaAs MESFET integrated circuits. They prevent diffusion of subsequent interconnection layers and so maintain stable low resistance (0.05 ohm. mm) contacts. The assessment of these contact structures, both electrically and using AES and TEM, is presented. The results show that the barrier action is effective in producing uniform and reliable contacts and good yields of MSI high speed digital circuits.

Abstract: The rare‐earth metals Yb and Sm show unique reactive behavior on mercury–cadmium–telluride (MCT) surfaces, due to the large rare‐earth affinity for both Hg and Te. Semiempirical calculations of thermodynamic parameters using Miedema’s model suggest that the rare earths should act as effective diffusion barriers at the interface between MCT and prototypical reactive metals such as Al, In, or Cr. We present here a synchrotron radiation photoemission investigation of the effect of Yb interlayers at the Hg1−xCdxTe(110)/Al junction. Our results indicate that layers of Yb are effective in preventing Al–Te reaction and reducing the Al‐induced mercury depletion of the substrate. Our data confirm that such a diffusion barrier effect is the result of the superior thermodynamic stability of the MCT/Yb reaction products at the interface.

Abstract: The invention is a layered nonalloyed ohmic contact structure for use on n type gallium arsenide including a layer of germanium or silicon of the order of 10 Å thick evaporated onto the gallium arsenide; a diffusion barrier layer of material 100-200 Å thick over the germanium or silicon selected from non-metallic conducting compounds, including metal compounds of arsenide phosphide carbide boride nitride silicide and non-metallic conducting elements; with the diffusion barrier layer material characterized by resistivity of the order of 1 ohm cm or less; and a conducting metal overlayer on the diffusion barrier layer. The invention includes the method for manufacturing the contact structure.