Abstract
Our recent study respecting chemical vapor deposition of (Ba, Sr)TiO3 thin films was discussed focusing on conformal deposition technique and composition control. Perfect conformal (Ba, Sr)TiO3 films were deposited under the kinetically limited condition using Ba(THD)2-Sr(THD)2-TiO(THD)2 (THD is 2,2,6,6-tetramethyl-3,5-heptanedione) source system. We successfully fabricated three-dimensional capacitors using this conformal deposition technique. Under the kinetically limited condition, the Ba/Sr composition ratio was determined by the partial pressure ratio of Ba(THD)2 and Sr(THD)2. The self-matching of Ti/(Ba+Sr) stoichiometry occurred under a certain TiO(THD)2 supply range. It was proposed that the possible important reactant species were (THD)2Ba-O-Ti(THD)2 and (THD)2Sr-O-Ti(THD)2 dimers.