(100) Strontium bismuth tantalate (SBT) SrBi2Ta2O9 films(similar to 114-234 nm thickness) on (111) Pt deposited by chemical solution deposition (CSD) and chemical vapor deposition (CVD) were investigated with tapping mode scanning force microscopy (TMSFM). The domain structure was found to be strongly influenced by film composition and defect density. Ideal samples showed an a-axis-oriented material with in-plane 180 degrees domains of similar to 22 nm width (film thickness 180-225 nm). The domains were visible by a surface corrugation of 0.5-2 nm downwards at the site of domain walls, which followed [001] planes. In samples with slightly higher defect density in-plane 180 degrees domains, normal-to-plane 180 degrees domains (similar to 10 nm difference in corrugation between differently poled domains) and 90 degrees domains (similar to 5 nm difference in corrugation between differently poled domains) occurred. Finally, for (100) SET samples, which deviated from the ideal composition by several percent, this very high defect density precluded the ordered formation of domain walls. Instead, as-grown a(1) and a(2)-axis oriented SET films showed random orientation of whole crystallites poled either in or normal to the surface. The observed surface corrugation between two differently poled crystallites was > 10 nm. Single crystallites as well as single domains could be activated and their polarization state was switched mechanically with an electron beam deposited (EBD) or a plasma-sharpened silicon supertip (SSS) by a force of similar to 5 nN.