Abstract
The surface morphologies of SrTiO3 substrates have been investigated by atomic force microscopy. Periodic step arrays could be developed on both normal and vicinal SrTiO3 (100) substrates by a new method employed both buffered NH4F-HF (BHF) solution and O2 annealing. An explanation is given for the surface morphologies observed which involves the surface stoichiometrical change upon BHF solution and surface diffusion upon oxygen annealing.