Large Area Circuit Delayering from the Backside Using Chemically Assisted Focused Ion Beam Sputtering with Optical Metrology Feedback

Abstract Advanced node semiconductor reverse engineering has always demanded cutting-edge techniques to cleanly extract the key structural information from the integrated circuit (IC) design. Core circuit edit technologies such as taking a backside wafer approach, employing scanning focused ion beam (FIB) recipes, optimized chemical delivery, and endpoint technology based on ultraviolet (UV) photon spectroscopy can play an important role in success. Once delayered, the IC's structural layers can be subjected to high-resolution scanning electron microscope (SEM) imaging. A new tool has been developed that incorporates these capabilities for dedicated IC delayering. These capabilities allow for the visualization of individual layers, transistors, interconnects, and other critical elements at nanometer-scale resolution, unveiling valuable insights into the IC's design and functionality.