Failure Analysis of RF Switches Combining FIB Circuit Modification and OBIRCH Localization

The radio frequency (RF) switch is a commonly used component in RF circuits, designed to facilitate the switching between different signal paths. In an RF switch, the gate typically controls the bias voltage, while the source and drain serve as the input and output for the RF signals, respectively. This paper primarily investigates RF switches that exhibit the failure mode of excessive insertion loss. It employs localization techniques such as Emission Microscopy (EMMI) and Optical Beam Induced Resistance Change (OBIRCH) to pinpoint the logic control circuit section within the RF switch, ultimately utilizing Focused Ion Beam (FIB) technology to observe the specific failure morphology. In the context of integrated circuit failure analysis cases, when confronted with the failure phenomenon where port leakage cannot be directly tested and EMMI localization shows no discrepancy, it is necessary to integrate the circuit modification capability of FIB to test the internal circuitry of the RF switch for failure localization.