Stress-induced device degradation due to die-attachment process after areabump formation

This paper presents the effect of stress on device degradation in metal-oxi de-semiconductor field-effect transistors (MOSFETs) due to the die-attachme nt process after area bump formation. Device degradation increases with inc reasing stress induced by die-attachment onto an area bump sample. The degr adation results mainly from interface trap generation at the Si-SiO2 interf ace and also from electron trapping in the gate oxide. It is clarified chat post-baking at 300 degrees C eliminates the degradation. However, the degr adation due to the potting material appears again after post-baking. Theref ore, in order to decrease the amount of device degradation due to the packa ging process, both the post-baking condition and potting material need to b e taken into account when a packaging technology with area bump formation i s used.