END-POINT DETECTION FOR FIB CIRCUIT MODIFICATION

A Focused Ion Beam (FIB) milling end-point detection system uses a constant current power supply to energize an Integrated Circuit (IC) that is to be modified. The FIB is cycled over a conductive trace that is to be accessed during the milling process. The input power, or voltage to the IC is monitored during the milling process. The end-point can be detected when the FIB reaches the conductive trace. The FIB can inject charge onto the conductive trace when the FIB reaches the level of the conductive trace. An active device coupled to the conductive trace can amplify the charge injected by the FIB. The active device can operate as a current amplifier. The change in IC current can result in an amplified change in device input voltage. The end-point can be detected by monitoring the change in input voltage from the constant current power supply.