High-Quality Passive Voltage Contrast Imaging Enabled by a Novel Integrated Low-Angle Ion Milling–SEM Delayering System
High-Quality Passive Voltage Contrast Imaging Enabled by a Novel Integrated Low-Angle Ion Milling–SEM Delayering System
Thursday, October 8, 2026: 9:40 AM
Summary:
The passive voltage contrast (PVC) method is one of the effective methods for failure analysis of semiconductor devices using scanning electron microscope (SEM). To analyze each layer of multilayer semiconductor devices, delayering techniques are also important methods. low-angle ion milling (LAIM) is suitable for obtaining VC images. However, when using a standalone LAIM system, the sample is exposed to the atmosphere during transfer to the SEM, resulting in contamination due to gas molecules adhering to the sample surface during observation. We propose an integrated SEM and LAIM system that enables seamless post-delayering observation and analysis. In this study, we have developed a LAIM-SEM delayering system equipped with a high resolution semi-in-lens SEM capable of acquiring VC images, along with an Argon ion source. Using this system, a SRAM sample was successfully delayered with minimal artifacts and contamination, enabling high-clarity PVC imaging. If a short circuit or insulation failure is present in the circuit, it is expected that a characteristic voltage contrast will be observed. This system enables observation with significantly reduced artifacts and contamination. This system has the potential to significantly enhance the effectiveness of semiconductor failure analysis.
The passive voltage contrast (PVC) method is one of the effective methods for failure analysis of semiconductor devices using scanning electron microscope (SEM). To analyze each layer of multilayer semiconductor devices, delayering techniques are also important methods. low-angle ion milling (LAIM) is suitable for obtaining VC images. However, when using a standalone LAIM system, the sample is exposed to the atmosphere during transfer to the SEM, resulting in contamination due to gas molecules adhering to the sample surface during observation. We propose an integrated SEM and LAIM system that enables seamless post-delayering observation and analysis. In this study, we have developed a LAIM-SEM delayering system equipped with a high resolution semi-in-lens SEM capable of acquiring VC images, along with an Argon ion source. Using this system, a SRAM sample was successfully delayered with minimal artifacts and contamination, enabling high-clarity PVC imaging. If a short circuit or insulation failure is present in the circuit, it is expected that a characteristic voltage contrast will be observed. This system enables observation with significantly reduced artifacts and contamination. This system has the potential to significantly enhance the effectiveness of semiconductor failure analysis.