Published online by Cambridge University Press: 01 February 2011
This work shows that the addition of dielectric levels in interconnect stacks increases significantly the CMP-induced peeling. The fracture energies, measured by 4-point bending technique, are less sensitive to the level number increase, even if they are slightly degraded. This leads to the conclusion that delamination during polishing depends highly on the stack elastic properties and there is no simple correlation between stack adhesion and peeling during CMP. In this work, mechanical damages generated during CMP in the dielectric stack before peeling were also investigated. It was shown that, if no peeling appears, CMP have no effect on stack reliability. This indicates that negligible “fatigue” effect takes place during CMP.