Microstructure of c-axis EuBa sub(2)Cu sub(3)O sub(y) thin films observed with scanning electron microscopy

The surface microstructure of c-axis EuBa sub(2)Cu sub(3)O sub(y) thin films sputtered onto MgO (001) are characterized by high-resolution scanning electron microscopy (SEM). The SEM images of films grown at a substrate temperature T sub(s) of 600 degree C, which is lower than our optimum T sub(s)(650 degree C) for c-axis growth, clearly show evidence of growth steps and spirals at the film surface. The heights of growth steps estimated from the tilted views are 4-5 nm, which correspond to 3-4 unit cells of the c-axis.