A Backside Functional OBIRCH Analysis Approach for High Precision Defect Localization in Digital Logic Blocks
A Backside Functional OBIRCH Analysis Approach for High Precision Defect Localization in Digital Logic Blocks
Wednesday, October 7, 2026: 12:20 AM
Summary:
Defect localization within digital circuit block is challenging, since complex and dense logic gate circuitries make traditional circuit probing almost infeasible. Photon emission microscopy (PEM) often produces multiple emission sites, requiring extensive circuit analysis to identify the functionally relevant defect. Conventional Optical Beam Induced Resistance Change (OBIRCH), particularly effective for static leakage localization, is not commonly used for pattern-dependent digital failures. This paper presents three production failure case studies demonstrating the use of backside functional OBIRCH for high‑precision localization of digital logic defects by biasing digital circuits under functional conditions. By combining backside infrared OBIRCH with external power sources and optimized test patterns, the circuit is driven into a failing logic state while localized changing current was detected. These cases demonstrate how backside functional OBIRCH quickly and successfully pinpoints digital defect locations. Compared to PEM‑only or conventional OBIRCH approaches, this method significantly reduced analysis complexity and improved localization accuracy and success rate.
Defect localization within digital circuit block is challenging, since complex and dense logic gate circuitries make traditional circuit probing almost infeasible. Photon emission microscopy (PEM) often produces multiple emission sites, requiring extensive circuit analysis to identify the functionally relevant defect. Conventional Optical Beam Induced Resistance Change (OBIRCH), particularly effective for static leakage localization, is not commonly used for pattern-dependent digital failures. This paper presents three production failure case studies demonstrating the use of backside functional OBIRCH for high‑precision localization of digital logic defects by biasing digital circuits under functional conditions. By combining backside infrared OBIRCH with external power sources and optimized test patterns, the circuit is driven into a failing logic state while localized changing current was detected. These cases demonstrate how backside functional OBIRCH quickly and successfully pinpoints digital defect locations. Compared to PEM‑only or conventional OBIRCH approaches, this method significantly reduced analysis complexity and improved localization accuracy and success rate.