In oxide electronics substrates with atomically flat terraces are a request for growing high-quality epitaxial thin films. In this paper results on chemical etching of some substrates with perovskite, ABO{sub}3, structure (e.g., SrTiO{sub}3, LSAT - the (LaAlO{sub}3)0.3(Sr{sub}2AlTaO{sub}6)0.35 solid solution, and NdGaO{sub}3) are presented. In order to obtain high quality substrates, different etchants (NH{sub}4F + HF, HCl + NH{sub}4Cl, and HCl + HNO{sub}3) with various pH values have been studied. From Atomic Force Microscopy (AFM), in air, we conclude that, irrespective of the etchant that has been used, a substrate surface with a BO{sub}x terminated layer and atomically flat terraces without etch pits could be obtained. The pH-value and temperature of the etchant and the etching time, however, influence significantly the surface quality. Reflection high energy electron diffraction (RHEED) patterns confirmed the AFM results.
展开▼
