Maximum Permissible EB Acceleration Voltage for SEM-Based Inspection Before Electrical Characterization of Advanced MOS

The electron beam based inspection instruments such as the review-SEM are widely used to analyze defects during manufacturing and failure analysis of scaled devices. Nano-probers used for scaled device analysis also employs SEM for probe guidance. However, electron beam (EB) induced damages are increasing with the scaling. A higher SEM resolution induces device damage. To avoid the damage, the acceleration voltage should be lower. Several generations of scaled devices from 350nm to 65nm were examined, and critical EB acceleration voltage that induced device degradation was quantitatively evaluated. The determination mechanism of permissible electron beam acceleration voltage is clarified.