The field dependence of electron beam induced current in thin oxide (22.5 nm) capacitors has been studied with a view of using the induced current for detecting defects in such devices. Results indicate that the induced current follows Fowler–Nordheim tunneling behavior when the field exceeding 4 MV/cm, and that a certain type of defect in thin oxide capacitors can be imaged with high contrast and low noise. A high current gain (∼103) of the induced current was also obtained. These findings open the possibility of acquiring information on the quality and reliability of composite metal‐insulator‐metal/semiconductor structures, and of achieving a high current for signal amplification.