Published online by Cambridge University Press: 10 February 2011
One of the key factors affecting the long-term reliability of thin film structures in microelectronics devices is the fracture resistance of their interfaces. Of the many different interfaces formed during device fabrication, the SiO2/TiN interface is amongst the most common. In order to measure the fracture energy of this interface, we have been utilizing a test in which a narrow strip of a material, having a large intrinsic tensile stress, is deposited and lithographically defined onto the SiO2/TiN/Al thin film structure. The elastic strain energy in the micro-strip provides an additional driving force to debond the weakest interface in the structure. Decohesion occurs when the thickness of the micro-strip, and hence the total elastic strain energy, exceeds a critical value. Another measure of the fracture resistance in the same test is the length of the strip that remains intact after debonding at both ends. This is a function of the intrinsic stress, the thickness of the superlayer, and the modulus ratios. In addition to presenting results on the measured fracture energy of the SiO2/TiN interface, evidence for stress-corrosion will be described.