We have used high-temperature scanning tunneling microscopy (STM) to study in real time SrTiO3 step edge dynamics in the 600 degrees C to 800 degrees C temperature range. We observed a dramatic transformation of the step edge structure above 690 degrees C, involving step edge straightening due to rapid migration of surface atoms. The STM study shows that if a NH4F-HF-etched substrate is annealed at 800 degrees C, a well-ordered surface, suitable for high-T-c superconductor thin film deposition, can be produced.