No abstract

Thermal stability of via resistance in the multilevel dual damascene Cu interconnection was investigated. The via resistance stability strongly depends on via size, via density and width of connecting Cu wires. The significant via-resistance shift was introduced by stressinduced voiding. To avoid the voiding failure, optimization of heat treatments after electroplating (EP)-Cu deposition are necessary for both stability of Cu films and adhesion of barrier layer with Cu. Thermal stress balance between Cu wires and inter-level-dielectric (ILD) is also important to suppress the via degradation. The dual damascene structure with lower-stress and lower-Young's modulus ILD films such as FSG can provide wider process windows for the stability of the via resistance.

No abstract

An axial self-bearing motor is proposed which can drive an axial blood pump without physical contact. It is a functional combination of the bi-directional disc motor and the axial active magnetic bearing, where it actively controls single degree-of-freedom motion, while other motions such as lateral vibration are passively stable. For application to a blood pump, the proposed self-bearing motor has the advantages of simple structure and small size. Through the finite element method (FEM) analysis and the experimental test, its good feasibility is verified. Finally, the axial flow pump is fabricated using the developed magnetically suspended motor. The pump test is carried out and the results are discussed in detail.