Published online by Cambridge University Press: 17 March 2011
In this work, the adhesion of CVD dielectric caps to ULK MSQ spin-ondielectric materials with k values of 2.2 and 2.0, and a ULK CVD materialwith a k value of 2.7 is presented. A substantial improvement in capadhesion to both the k2.2 ULK MSQ and the k2.7 ULK CVD material isdemonstrated. The improvement is obtained using a low-k CVD glue materialbetween the ULK dielectric and the subsequent cap material and/or byoptimizing the CVD cap film deposition. Four-point bend measurement ofadhesion strength is used to quantify the improvement in interface adhesion.The improvement in CVD cap adhesion is demonstrated to be strongly dependentupon both the glue layer film and the cap deposition conditions. Whileoptimization of the CVD cap materials results in adequate adhesion for thek2.2 ULK MSQ, these improvements are demonstrated not to extend to the k2.0ULK MSQ film.