Voltage choosing of OBIRCH for finger metal structure

摘要

As a tool to localize defects, OBIRCH is widely used in solving the problem of FAB low yield issue. Choosing a proper voltage is critical for the effective working of OBIRCH. This paper proposes a method to analyze the critical voltage of OBIRCH used to the finger metal structure. Based on the measurement data including current and voltage, an empirical formula has been simulated to calculate Sigma (current comparative difference). Three cases show proper voltage arises while the Sigma had the maximum value. It is proved that the method proposed is effective to choose a correct voltage for the working of OBIRCH.