With decreasing transistor sizes accurate failure localization becomes more and more important in order to find the root cause of failures with high efficiency. Field returns are a special challenge, since there is usually only one sample for preparation. Hence, reliable high resolution localization is mandatory for a successful preparation. Optical beam induced resistance change (OBIRCH) is a powerful tool for localization but has resolution limitations due to the diameter of the optical beam. The tool can be further improved by the lock-in technique. In this paper we demonstrate that the lock-in technique can also be applied for electron beam localization methods like electron beam induced current (EBIC) / electron beam absorbed current (EBAC) and resistance change imaging (RCI) / electron beam induced resistance change (EBIRCH).