Surface Oxidation Behavior of TiN Film Caused by Depositing SrTiO 3 Film

TiN thin films are prepared by rf magnetron sputtering in order to examine their applicability as bottom electrodes of dynamic random access memory (DRAM) capacitors. On the TiN thin films, SrTiO3 thin films are deposited in various O2/(Ar+O2) sputtering gas flow ratios and substrate temperatures, and the amount of TiN which is converted to oxide during SrTiO3 deposition is evaluated from the change in its resistance. Thickness of the oxidized TiN was reduced from 43 nm to 7 nm by decreasing the O2 flow ratio from 100% to 0% and decreasing the substrate temperature from 400°C to 300°C during SrTiO3 deposition. The applicability of the TiN thin film as a bottom electrode of DRAM capacitors is discussed.