Pattern Design to Prevent Sawing-Induced Passivation Damage on Scribe Region During Semiconductor Wafer Separation

Abstract

This work details how devices mechanically separated from wafers with a dummy pattern in their scribe region can undergo serious reliability degradation due to Si₃N₄ damage. Experimentally, it was found that although chipping damage occurs only within the scribe region, Si₃N₄ damage can grow up to the active region, which is far away, beyond the chipping damage range, because inappropriate Si₃N₄ coverage in the scribe region can be a carrier for damage propagation during sawing. Further, this work shows that Si₃N₄ damage existing in the scribe region even after wafer separation completion can further attack the active region and cause device failure during thermal-cycling. So, this work suggests that appropriate design of the amorphous Si₃N₄ layer in the scribe region is essential in order to allow the devices to have better reliability margins during thermal-cycling as well as mechanical wafer separation.