The recent introduction of dual inlaid Cu and oxide based interconnects within sub-0.25μm CMOS technology has delivered higher performance and lower power devices. Further speed improvements and power reduction may be achieved by reducing the interconnect parasitic capacitance through integration of low-k interlevel dielectric (ILD) materials with Cu. This paper demonstrates successful multi-level dual inlaid Cu/low-k interconnects with ILD permittivities ranging from 2.0 to 2.5. Integration challenges specific to inorganic low-k and Cu based structures are discussed. Through advanced CMP process development, multi-level integration of porous oxide materials with moduli less than 0.5 GPa is demonstrated. Parametric data and isothermal annealing of these Cu/ low-k structures show results with yield comparable to Cu/oxide based interconnects.

The recent introduction of dual inlaid Cu and oxide based interconnects within sub-0.25μm CMOS technology has delivered higher performance and lower power devices. Further speed improvements and power reduction may be achieved by reducing the interconnect parasitic capacitance through integration of low-k interlevel dielectric (ILD) materials with Cu. This paper demonstrates successful multi-level dual inlaid Cu/low-k interconnects with ILD permittivities ranging from 2.0 to 2.5. Integration challenges specific to inorganic low-k and Cu based structures are discussed. Through advanced CMP process development, multi-level integration of porous oxide materials with moduli less than 0.5 GPa is demonstrated. Parametric data and isothermal annealing of these Cu/ low-k structures show results with yield comparable to Cu/oxide based interconnects.

Powder metallurgy (P/M) involves a multiple-step process to prepare and consolidate granulated metal and composites into near-net-shaped components. The modern P/M method starts with a precisely defined final geometry and a set of properties for a desired component. Decisions are then made about a variety of processing variables, recognizing that many variables strongly interact counter to the desired properties. Finally preproduction fabrication trials are conducted to optimize key variables until he specifications are achieved, and the processing conditions are established. A critical step in the overall process is the compaction of powder into a sufficiently strong, low-porosity, properly shaped part with uniform microstructure that can be sintered, or alternately heated and pressed to the final dimensions and properties.

The technique of microscope examination and hot wire cautery in a prospective study of 100 consecutive patients with acute epistaxis is described. The method was successful in arresting haemorrhage in 94 per cent of patients bleeding at the time of examination, and in 86 per cent, discharge home within one hour was possible. Due to improved illumination, magnification and control of the cautery instrument, nasal packing was required in only nine per cent of cases. By achieving this and by reducing the overall need for admission to 20 per cent, we recommend this method of treatment both as a successful cost saving measure, as well as advantageous to the patient.

The γ-ray burst brightness distribution is inhomogeneous and the distribution on the sky is nearly isotropic. These features argue against an association of γ-ray bursts with those Galactic objects that are known to exhibit a strong concentration toward the Galactic center or plane. The observed statistical properties indicate a cosmological origin. Circumstantial evidence suggests that neutron stars are involved in the burst phenomenon. Here we consider Population II neutron stars in an extended Galactic Halo (EGH) as an alternative to cosmological scenarios. The BATSE data indicate a small deviation from isotropy near the 2 σ level of statistical significance. If confirmed for an increasing number of bursts, these anisotropies could rule out cosmological scenarios. On the other hand, EGH models require small anisotropies like those observed by BATSE. We consider simple distribution models to determine the generic properties such halos must have to be consistent with the observations and discuss the implications of the corresponding distance scale on burst models.

Subject headings: gamma rays: bursts — stars: neutron — stars: Population II — stars: statistics

A strong correlation has been established between TiN substrate anneal ambient and electromigration performance of Al-based alloys. Excellent electromigration lifetimes were measured for AlSiCu (and AlCu) films on sputtered TiN substrates annealed in N2 and slowly cooled down in furnace. The films annealed in N2-O2 and N2-H2 showed poorer electromigration performance, in that order. Stronger Al (111) texture, larger median grain size and uniform grain size distribution have been responsible for the improved electromigration performance of the N2-annealed (furnace-cooled) films. On the contrary, Al alloy films on TiN substrates annealed in N2 (but air-cooled), N2-O2, or N2-H2 ambient showed weaker Al (111) textures and smaller median grain sizes.

When protogalaxies collapse, the cooling and infall of what will become the visible galactic component affects the mass distribution of dissipationless dark matter particles which constitute the halo. For spiral galaxies, the reaction of the dissipationless halo can have a striking effect on the resulting rotation curves [1–5].