Published online by Cambridge University Press: 15 February 2011
In a Mixed-Signal IC, both digital and analog circuits exist on the same chip. Analog circuit blocks require technology attributes like precise device matching, low parametric drifts and low noise. These requirements raise additional reliability issues, over and above the reliability concerns associated with digital circuits. CMOS device reliability for mixed-signal technologies can be enhanced by modifying device architecture and improving gate oxide integrity. Interconnect metallurgy plays an important role in determining electromigration related contact/via resistance change which may impact matching of devices and resistor pairs. Appropriate source/drain engineering, device design and utilizing nitrided gate oxide has been shown to produce extremely stable devices. This article will cover process architecture and material issues related with device stability and interconnect metallurgy issues related with contact/via stability, especially with W-Plugs.