Abstract: Methods and devices are provided for absorber layers formed on foil substrate. In one embodiment, a method of manufacturing photovoltaic devices may be comprised of providing a substrate comprising of at least one electrically conductive aluminum foil substrate, at least one electrically conductive diffusion barrier layer, and at least one electrically conductive electrode layer above the diffusion barrier layer. The diffusion barrier layer may prevent chemical interaction between the aluminum foil substrate and the electrode layer. An absorber layer may be formed on the substrate. In one embodiment, the absorber layer may be a non-silicon absorber layer. In another embodiment, the absorber layer may be an amorphous silicon (doped or undoped) absorber layer. Optionally, the absorber layer may be based on organic and/or inorganic materials.

Abstract: The mechanism of forming a metal bump structure described above resolves the delamination issues between a conductive layer on a substrate and a metal bump connected to the conductive layer The conductive layer can be a metal pad, a post passivation interconnect (PPI) layer, or a top metal layer By performing an in-situ deposition of a protective conductive layer over the conductive layer (or base conductive layer), the under bump metallurgy (UBM) layer of the metal bump adheres better to the conductive layer and reduces the occurrence of interfacial delamination In some embodiments, a copper diffusion barrier sub-layer in the UBM layer can be removed In some other embodiments, the UBM layer is not needed if the metal bump is deposited by a non-plating process and the metal bump is not made of copper

Abstract: A 3-aminopropyltrimethoxysilane-derived self-assembled monolayer (NH 2 SAM) is investigated as a barrier against copper diffusion for application in back-end-of-line (BEOL) technology. The essential characteristics studied include thermal stability to BEOL processing, inhibition of copper diffusion, and adhesion to both the underlying SiO 2 dielectric substrate and the Cu over-layer. Time-of flight secondary ion mass spectrometry and X-ray spectroscopy (XPS) analysis reveal that the copper over-layer closes at 1-2-nm thickness, comparable with the 1.3-nm closure of state-of-the-art Ta/TaN Cu diffusion barriers. That the NH 2 SAM remains intact upon Cu deposition and subsequent annealing is unambiguously revealed by energy-filtered transmission electron microscopy supported by XPS. The SAM forms a well-defined carbon-rich interface with the Cu over-layer and electron energy loss spectroscopy shows no evidence of Cu penetration into the SAM. Interestingly, the adhesion of the Cu/NH 2 SAM/SiO 2 system increases with annealing temperature up to 7.2 J m -2 at 400°C, comparable to Ta/TaN (7.5 J m -2 at room temperature). The corresponding fracture analysis shows that when failure does occur it is located at the Cu/SAM interface. Overall, these results demonstrate that NH 2 SAM is a suitable candidate for subnanometer-scale diffusion barrier application in a selective coating for copper advanced interconnects.

Abstract: A method and structure for good adhesion of Intermetallic Compounds (IMC) on Cu pillar bumps are provided. The method includes depositing Cu to form a Cu pillar layer, depositing a diffusion barrier layer on top of the Cu pillar layer, and depositing a Cu cap layer on top of the diffusion barrier layer, where an intermetallic compound (IMC) is formed among the diffusion barrier layer, the Cu cap layer, and a solder layer placed on top of the Cu cap layer. The IMC has good adhesion on the Cu pillar structure, the thickness of the IMC is controllable by the thickness of the Cu cap layer, and the diffusion barrier layer limits diffusion of Cu from the Cu pillar layer to the solder layer. The method can further include depositing a thin layer for wettability on top of the diffusion barrier layer prior to depositing the Cu cap layer.

Abstract: Adhesive layers residing at an interface between metal lines and dielectric diffusion barrier (or etch stop) layers are used to improve electromigration performance of interconnects. Adhesion layers are formed by depositing a precursor layer of metal-containing material (e.g., material containing Al, Ti, Ca, Mg, etc.) over an exposed copper line, and converting the precursor layer to a passivated layer (e.g., nitridized layer). For example, a substrate containing exposed copper line having exposed Cu—O bonds is contacted with trimethylaluminum to form a precursor layer having Al—O bonds and Al—C bonds on copper surface. The precursor layer is then treated to remove residual organic substituents and to form Al—N, Al—H bonds or both. The treatment can include direct plasma treatment, remote plasma treatment, UV-treatment, and thermal treatment with a gas such as NH 3 , H 2 , N 2 , and mixtures thereof. A dielectric diffusion barrier layer is then deposited.

Abstract: This paper studies the coating geometries of metals on single-walled carbon nanotubes (SWNTs) on the basis of the nucleation theory and wetting theory. The metal surface energy, cohesion energy, diffusion barrier, and metal-SWNT interfacial energy are calculated using first-principles calculation. Metals including Fe, Al, Au, Pd, Ni, and Ti are considered. For Ti, Ni, and Pd, low metal-SWNT interfacial energies and high diffusion barriers are responsible for forming continuous or quasicontinuous layers on the SWNT surface. In contrast, Al and Au have small diffusion barriers and poor SWNT surface wetting, thus they tend to aggregate and form large clusters. Although the binding energy between Fe and SWNTs is large, due to the large cohesion energy and poor wetting, Fe may form isolated clusters. All results are in good agreement with experimental observations.

Abstract: An enhancement-mode GaN transistor, the transistor having a substrate, transition layers, a buffer layer comprised of a III Nitride material, a barrier layer comprised of a III Nitride material, drain and source contacts, a gate containing acceptor type dopant elements, and a diffusion barrier comprised of a III Nitride material between the gate and the buffer layer.

Abstract: Fundamental material interactions as pertinent to nano-scale copper interconnects were studied for CVD Co with a variety of micro-analytical techniques. Native Co oxide grew rapidly within a few hours (XPS). Incorporation of oxygen and carbon in the CVD Co films (by AES and SIMS) depended on underlying materials, such as Ta, TaN, or Ru. Copper film texture (by XRD) and agglomeration resistance (by AFM) showed correlations with amounts of in-film oxygen/carbon. Cobalt diffused through copper at normal processing temperatures (by SIMS). CVD Co demonstrated diffusion barrier performance to Cu (by Triangular Voltage Sweep, TVS), but not to O 2 . CVD Co was applied to 32 nm/22 nm damascene Cu interconnect fabrication in a scheme defined by the material studies. Lower post-CMP defect density and longer electromigration lifetimes were obtained.

Abstract: Apparatus and methods for filling through silicon vias (TSV's) with copper having an intervening tungsten layer between the copper plug and the silicon are disclosed. Methods are useful for Damascene processing, with or without a TSV feature. The tungsten layer serves as a diffusion barrier, a seed layer for copper electrofill and a means of reducing CTE-induced stresses between copper and silicon. Adhesion of the tungsten layer to the silicon and of the copper layer to the tungsten is described.

Abstract: To improve temperature durability for autoclaving of SiOx diffusion barrier coatings on polypropylene, plasma polymerized hexamethyldisiloxane (pp-HMDSO) is applied by plasma enhanced chemical vapour deposition as interlayer material and compared with results obtained with amorphous hydrogenated carbon-nitrogen (a-C : N : H) and a-Si : C : O : N : H interlayers. The influence of the O2/HMDSO ratio on the chemical structure and related mechanical and oxygen barrier properties is investigated by fragmentation tests, dilatometry, oxygen transmission rate, internal stress and mass density measurements as well as Fourier transform infrared and x-ray photoelectron spectroscopy. Carbon-rich, polymer-like coatings with low density, low internal stress and excellent adhesive and cohesive properties are found for pp-HMDSO at the expense of barrier performance. In the SiO x/pp-HMDSO coating a broad transition in chemical composition was observed, explaining improved mechanical properties responsible for good barrier performance after thermal cycling or autoclaving.

Abstract: In a semiconductor device, an insulating interlayer having a groove is formed on an insulating underlayer. A silicon-diffused metal layer including no metal silicide is buried in the groove. A metal diffusion barrier layer is formed on the silicon-diffused metal layer and the insulating interlayer.

Abstract: Ternary Ni-based amorphous films can serve as a diffusion barrier layer for Cu interconnects in ultralarge-scale integration (ULSI) applications. In this paper, electroless Ni–Mo–P films deposited on SiO 2 layer without sputtered seed layer were prepared by using Pd-activated self-assembled monolayer (SAM). The solutions and operating conditions for pretreatment and deposition were presented, and the formation of Pd-activated SAM was demonstrated by XPS (X-ray photoelectron spectroscopy) analysis and BSE (back-scattered electron) observation. The effects of the concentration of Na 2 MoO 4 added in electrolytes, pH value, and bath temperature on the surface morphology and compositions of Ni–Mo–P films were investigated. The microstructures, diffusion barrier property, electrical resistivity, and adhesion were also examined. Based on the experimental results, the Ni–Mo–P alloys produced by using Pd-activated SAM had an amorphous or amorphous-like structure, and possessed good performance as diffusion barrier layer.

Abstract: During the operation of solid oxide fuel cells (SOFCs) the Ni base anode and/or Ni-mesh is in direct contact with the ferritic steel interconnect or the metallic substrate. For assuring long-term stack operation a diffusion barrier layer with high electronic conductivity may be needed to impede interdiffusion between the various components. A preoxidation layer on the ferritic steel turned out to be not viable as a barrier layer since a Ni-layer tends to dissociate the oxide scale. Therefore the potential of ceria as a diffusion barrier layer for the anode side of the SOFC was estimated. The barrier properties of a ceria coating between the Ni and the ferritic steel Crofer 22 APU were tested for 1000 h in Ar-4H 2 -2H 2 O at 800°C. Conductivity experiments were performed in the same atmosphere at different temperatures. After long-term exposures no indication of interdiffusion between Ni and ferritic steel could be detected, however, sputtered coatings on ferritic steel substrates showed signiftcantly lower conductivities than bulk ceria samples because of void formation between the ceria and the oxide on the steel surface. The latter could be prevented by an intermediate copper layer, which resulted in overall area specific resistance values lower than 20 mΩ cm 2 after 100 h exposure at 800°C.

Abstract: The oxidation behavior of Ni–Cr–Fe-based alloys in a low oxygen partial pressure atmosphere (H2–H2O) was investigated in terms of the effect of alloy microstructure and their silicon content. It was found that the formation and growth kinetics of the oxide scale are rather sensitive to the alloy microstructure and their corresponding Si contents. Oxide ridges were found to form in areas with eutectic structure, while a thin and homogeneous oxide scale formed on austenite matrix. The thicknesses of the oxide ridges and the oxide layer on the austenite matrix were dependent of their corresponding Si contents. The austenite/carbide phase boundaries in eutectic structure can offer fast diffusion paths for metal outward diffusion, which leads to the formation of ridge-like oxide features. The continuous SiO2 sub-layer formed at the oxide scale/metal interface on the austenitic matrix acted as an effective diffusion barrier to metal outward diffusion, resulting in rather thin and uniform oxide scales.