1,721,053 research outputs found
Interaction between electromigration and mechanical-stress-induced migration: New insights by a simple, wafer-level resistometric technique
No full textThe unavoidable presence of mechanical stress in VLSI interconnect lines has a nonnegligible influence on the characterization of electromigration (EM). In this work a wafer level resistometric technique is applied as an indirect way to detect the combined effect of mechanical stress migration
and EM, the direct measurement of the former being difficult in narrow lines. In order to perform reliable high-resolution resistance measurements, a technique has been developed in which the compensation of small thermal instabilities is achieved by means of an additional measurement on a reference device. EM tests performed at constant temperature and current on Al-1%Si stripes exhibit an initial nonlinear resistance versus time behavior, probably due to the simultaneous action of the accumulated mechanical stress and the high current density, followed by linear behavior. An activation energy is extracted, using an original statistical analysis of the experimental data, and its meaning is discussed, taking into account temperature- and time-dependent mechanical stress influence. It is concluded that the kinetics of stress relaxation should be known more deeply in order to perform reliable operating temperature extrapolations from the calculated activation energies
Ohmic contact electromigration
No full textIn this paper ohnfic contact electromigration is briefly reviewed. After a short introduction on the main contact failure mechanisms and technological solutions, the effect of contact scaling on electromigration is considered. Then, guidelines on test structures and lifetest set-up for contact electromigration studies are given, with particular reference to the thermal characterization needed to extract rehable data from lifetest experiments. Finally, the most recent experimental results obtained with both aluminum based metallizations and contacts making use of silicides or barrier layers are reviewed and compared
The Resistance Decay after Electromigration as the Effect of Mechanical Stress Relaxation
No full textThe circular resistor (CR)-a novel structure for the analysis of VLSI contacts
No full textA novel structure, named Circular Resistor, is proposed
for extracting metal/semiconductor contact resistivity. A two-dimensional analytical solution of the system is shown in a simplified case; the complete solution is calculated by numerical simulations. Very good agreement between the analytical model and the numerical simulations was found. Regarding resolution, the Circular Resistor exhibits characteristics similar to other standard structures, but the circular shape allows to fit the actual geometry of VLSI contacts
Resistance decay after electromigration as the effect of mechanical stress relaxation
No full textResistance decay has been observed in Aluminum narrow lines when the high stressing current in electromigration tests is turned off. It has been interpreted as the consequence of the relaxation of eleetromigration-induced mechanical strese
A further comment on "Determining specific contact resistivity from contact end resistance measurements"
No full textThe purpose of this comment is to contribute to a better
understanding of the influence of lateral current crowding, sheet resistance, and interface pitting in the determination of the interface contact resistivity in four terminal resistor test patterns, for two different metallization schemes, i.e., Al/n+Si and (A1 + 1.5-percent Si)/n+S
Electrical characterization of the TiN/Ti/n+/Si (and p+/Si) interfaces by means of a circular resistor test structure
No full textA circular geometry based test structure for contact resistance measurements is introduced, together with a compact analytical model for contact resistivity extraction. The Circular Resistor (CR) structure is intended to be used for VLSI contacts that tend to a rounded shape due to lithographic effects
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