Measuring the Young’s modulus of ultralow-k materials with the non destructive picosecond ultrasonic method

Young’s modulus, which is a measure of elastic strength, provides a good predictor of an interlevel dielectric (ILD) film’s ability to withstand chemical mechanical polishing (CMP) and packaging stresses. Picosecond ultrasonics offers a high-throughput, non contact method to measure Young’s modulus that is compatible with inline process monitoring. Discussion of this technique and its capability to measure on PECVD non porogen porous a-SiOC:H films with good correlation with nanoindentation and ellipsometric porosimetry (EP) measurements will be presented.