(Ba,Sr)TiO3 thin film capacitors with Ru electrodes for application to ULSI processes

A low temperature Nz post-annealing process was proposed to improve the deg raded leakage characteristics of Ru/(Ba,Sr)TiO3/Ru capacitors due to formin g gas annealing. By using the N-2 post-annealing at 300 degreesC, the leaka ge current degraded by the forming gas annealing was completely recovered t o the initial level without affecting the SiO2 equivalent thickness of 0.51 nm. No degradation in the subthreshold characteristics of n-channel MOSFETs and N+P junction leakage current by the post-annealing was also confirmed. The Ru/(Ba,Sr)TiO3/Ru capacitor technology with this post-annealing proces s is suitable for DRAMs in 0.13 mum generations and beyond.