Use of voltage contrast to locate defects in patterned high-T_c films

Voltage contrast in a scanning electron microscope equipped with a liquid nitrogen temperature stage can be used for inspecting patterned lines of high-Tc films. The observation of voltage on lines of superconducting materials is helpful in rapidly locating material defects, or regions in which the critical current density is exceeded. Voltage can be induced either by forcing current through the lines or by the deposition of charge by the electron beam. Both methods make possible quick voltage observations on lines of a few microns or less.