Stress-Temperature Behavior and Stress Relaxation in Ti/Al-0.5%Cu/TiN and TiN/W Thin Films

The stress behavior of two structures (Ti/Al-0.5%Cu/TiN and TiN/W) has been analyzed versus temperature up to 400 °C using the Flexus measurement system. Microstructure modifications induce stress variations with temperature. Furthermore, stress relaxation after annealing has been investigated. Al-based metallization stress is essentially due to thermal issues and reaches rapidly its yield strength whereas the W film exhibits high intrinsic stress. Microstructural observations afte deposition and after annealing have been conducted using a non destructive technique, the Thermal Wave Imager.