Engineering Materials and Processes phần 10 pptx

Summary 117

Figure 7.4. RBS spectra (3.7 MeV He+2, 7° tilt) of the diffusion barriers before (broken line)

and after (solid line) testing at 620°C for 30 minutes in flowing atmosphere N2-5% H2

ambient [8]

7.3 Electromigration Resistance

Electromigration (EM) resistance of Ag is the most critical interconnect reliability

concern that would determine its suitability for integrated circuit technology. EM is

the drift of metal ions as a result of either collision between the conductor electrons

and/or the metal ions or high electrostatic field force when current is passed

through a metal conductor. The direction of mass transport depends on the

direction of the net force. When high current densities pass through the metal line,

voids or hillocks are formed at a point of ion flux divergence (Figure 7.5). Voids

and hillocks deform and grow until electrical failure is completed [10].