Using ultrasonics to measure the strength of porous ULK dielectrics

Low-k dielectric materials permit faster IC operation and improve electrical performance, but these materials are generally weaker and prone to mechanical failure. The mechanical strength is particularly low for porous dielectrics, so they are subject to failure during stressful manufacturing processes. Picosecond ultrasonics tools can rapidly measure the mechanical strength of porous dielectrics with k values approaching 2, and can resolve within-wafer uniformity. The technique can be used to develop more robust deposition processes and to control those processes in high-volume production.