Reaction paths and kinetics of aluminide formation in Al/epitaxial-W(001) model diffusion barrier systems
Single‐crystal bcc W(001) layers, 140 nm thick, were grown on MgO(001) substrates by ultrahigh‐vacuum (UHV) magnetron sputter deposition at Ts=600 °C. Al overlayers, 190 nm thick with strong (001) and (011) preferred orientation and an average grain size of 200 nm, were then deposited at Ts=100 °C without breaking vacuum. Changes in bilayer sheet resistance Rs were monitored continuously as a function of time ta and temperature Ta during UHV annealing. In addition, Rutherford backscattering spectroscopy, x‐ray diffraction, transmission electron microscopy (TEM), and scanning TEM, in which cross‐sectional specimens were analyzed by energy‐dispersive x‐ray analysis with a 1 nm resolution, were used to follow area‐averaged and local interfacial reaction paths as well as microstructural changes as a function of annealing conditions. The initial reaction products were discontinuous regions of monoclinic‐structure WAl4 which exhibit a crystallographic relationship with the underlying W layer. bcc WAl12 forms at...
General aspects of barrier layers for very-large-scale integration applications II: Practice
Abstract Metallization schemes used to establish electrical contact to the silicon in planar integrated circuits are reviewed with an emphasis on the role that diffusion barriers play in them. Some of the ideas that led to the development of metallization schemes in the past are retraced on the basis of examples ( e.g. beam lead technology, TiN, Ti: W, Ni/Cu). It is shown that the implementation often embodied concepts not initially recognized. The increased understanding of thin film phenomena that has resulted from the development of new analytical methods is likely to lead to corresponding improvements in future barrier layer designs.
Implementation of Tourism Satellite Account: Assessing the Contribution of Tourism to the Croatian Economy
Compiling the indicators of tourism consumption and the output of tourism industries, Tourism Satellite Account (TSA) provides a framework for internationally harmonized measurements of direct macroeconomic contribution of tourism. Ivandic and Marusic provide a detailed methodological approach for the transfer of TSA theoretical concepts to the assessment of tourism economic contribution on the case of the Croatia. Giving that the TSA compilation is still characterized by a surprisingly wide range of ‘styles’ used, the chapter contributes to a better understanding of the issues related to measurement of direct tourism impacts. It also gives a set of baseline criteria for resource allocation within tourism policy and the further evaluation of its effectiveness.