Polycrystalline barium titanate (BaTiO3) thin film with smooth surface was grown on silicon substrate at room temperature by using KrF laser ablation technique and KrF laser post‐annealing technique.Insituspectroscopic analysis of excited species in KrF laser‐induced plasma from BaTiO3was also examined and the distance between the target and the surface to fabricate stoichiometric thin films by KrF laser ablation was optimized to be 20 mm. The XRD patterns of BaTiO3thin films post‐annealed with a laser fluence of 0.11 J/cm2at a back pressure of oxygen of 100 mTorr showed the (100), (110), (111), (200), and (211) peaks. ©1996 American Institute of Physics.