Barrier properties of 10 nm thick Ru and amorphous Ru37.2W 62.8 films as seedless copper diffusion barriers have been investigated. Thermal stability of the barriers was evaluated after annealing at various temperatures. X-ray diffraction (XRD) analyses and sheet resistance measurements suggested that the Ru37.2 W62.8 barrier was thermally stable up to 700°C against Cu diffusion, which improved about 150°C over the Ru film. XRD studies and electron diffraction patterns of the Ru37.2W62.8 film showed that it maintained an amorphous-like microstructure after 30 min annealing at 550°C. This film started to recrystallize at about 600°C and developed to a film with Ru and WO3 grains after a 700°C anneal. The leakage current of the 500°C postannealed Cu/RuW/porous SiOCH/Si stacked structure provided nearly 2 orders of magnitude superior than that of the Ru sample. The amorphous Ru 37.2W62.8 film is an alternative candidate for the Cu direct platable seedless barrier in the advanced copper metallization process.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Materials Chemistry