[Show abstract][Hide abstract] ABSTRACT: A product with flip-chip package suffered from the ring-type yield loss at the wafer edge (Fig. 2(b)) and the failure analysis (FA) Ring-type yield loss at wafer edge has been observed during flip-showed the damage sites always located at some specific layouts of chip packaging process. The failure mechanism is attributed to the the internal circuits. However, other products in the same product scrubber clean process step which generates a lot of charges. This in line didn't suffer similar yield loss. Thus, this yield loss was sus-turn behaves like an electrostatic discharge (ESD) event and damages pected to be sensitive to the special layout. gate oxide of internal circuits. An equivalent circuit is proposed to analyze such a kind of ESD event and proves the importance of the parasitic capacitance of the interconnect metal.
[Show abstract][Hide abstract] ABSTRACT: In this paper, the impact of ball bonding (BB) induced voltage transient on the reliability test including electro-migration (EM), time dependent dielectric breakdown (TDDB), negative bias temperature instability (NBTI) and electro-static discharge (ESD) are investigated. During the electronic flame-off (EFO) of ball bonding process, a spark discharge current, which applies a high electric field between the wire and wand, is used to melt the wire to form a free air ball (FAB). In the mean time, however, the spark may generate ions in the air and some of them may charge to die for package. After free air ball was bonded to pad, a BB-induced voltage transient can be measured and may impose an electrical stress to devices, then to degrade the device lifetime if without suitable I/O protection circuits. The degradation mechanism can be considered as charge device model (CDM) electrostatic-discharge (ESD) event. To remove or reduce this package-induced damage, ionizers had been put closely to the bonding tool and showed very good package yield, compared to those without ionizer.