Ki-Yeol Park

Effect of mechanical strength and residual stress of dielectric capping layer on electromigration performance in Cu/low-k interconnects

We present the effect of mechanical strength and residual stress of dielectric barrier on electromigration performance in Cu/low-k interconnects. It has been discovered that mechanical strength and residual stress of dielectric capping layer have a great role on EM performance. The use of mechanically strong dielectric capping material with high residual compressive stress in Cu/low-k interconnects improves a structural confinement of Cu line. Also, it helps tensile stress level decrease near via bottom and compressive stress level increase at Cu beneath SiCN along Cu line. Reduction of tensile stress at via bottom would effectively suppress void nucleation and growth. Moreover, increase of compressive stress in Cu beneath SiCN alleviates Cu migration through that pathway, leading to a longer lifetime of interconnect component.

Analysis of DC/transient current and RTN behaviors related to traps in p-GaN gate HEMT

Trap-related transient characteristics and RTN in p-GaN gate HEMT were characterized, for the first time to our knowledge. Current conduction mechanism in DC IG is explained based on proposed model. Hopping conduction mechanism is responsible for IG at VG <; 0. IG at VG > 0 seems to be controlled by thermionic emission and affected by the action of floating-base n(W)-p(p-GaN)-n(AlGaN/GaN) bipolar transistor. Transient current behavior is related to the DC conduction mechanism and could be explained by thermal emission and charge trapping in p-GaN and AlGaN layers. Measured transient behavior of gate capacitance corresponds to that of the transient currents. Hole trapping into the AlGaN layer and existence of percolation path in gate and drain currents are verified by analyzing RTNs in IG and ID. Trap position and activation energy regarding RTN are firstly extracted. RTN time constants are similar to those in IG and ID transient behavior.