Overlap design for higher tungsten via robustness in AlCu metallizations

Abstract

Due to the miniaturization process of the CMOS components metallization structures are becoming more and more complex. Better knowledge to improve via robustness for high current applications is needed. Geometry changes can have a big effect on the physical behaviour. For higher robust metallization systems it is necessary to learn more about overlap design to meet the most economic layout. Slotted high current line layouts do not allow the use of big via areas. Furthermore the number of vias increases the resistance. Investigations have shown the existence of an optimal overlap.