The microstructures of Hg-based cuprate thin films have been studied u
sing a scanning electron microscope and an energy dispersive X-ray spe
ctrometer, Besides a rough surface, several types of defects including
the HgCaO2 phase are identified on those films made using a slow temp
erature ramping Hg-vapor annealing process. By ramping the sample temp
erature rapidly to the annealing temperature, the surface morphology o
f the film is significantly improved and the impurity phases, especial
ly the HgCaO2 phase, are effectively reduced.