Reliability improvements of TiN/Al2O3/TiN for linear high voltage metal–insulator–metal capacitors using an optimized thermal treatment

Abstract

Metal–insulator–metal (MIM) capacitors with TiN and high thickness of Al2O3 above 50 nm were fabricated to address high voltage (>30 V) and linear capacitor applications. Atomic layer deposition is used to deposit both TiN and Al2O3 to guarantee a good composition and thickness control. The impact of the deposition process and post-treatment condition on the MIM capacitor's breakdown voltage is studied and correlated with time of flight-secondary ion mass spectrometry (ToF-SIMS). Higher deposition temperature and thermal treatment of TiN and Al2O3 after deposition increase breakdown voltage and improve uniformity. ToF-SIMS demonstrates that Al2O3 higher deposition temperature or rapid thermal processing annealing reduce the diffusion of TiN in Al2O3 leading to thinner TiN/Al2O3 interface layers that influence breakdown voltage and uniformity.