Localization of Capacitive Open Defects Using ThermoDynamic Imaging
Localization of Capacitive Open Defects Using ThermoDynamic Imaging
Wednesday, October 7, 2026: 9:00 AM
Summary:
Continued device scaling and three-dimensional integration in semiconductor devices have significantly increased the difficulty of fault localization. In particular, open-like high-resistance defects are difficult to detect using conventional low-frequency thermal analysis because only limited steady-state current flows through the defective path, resulting in weak heat generation. To address this challenge, we investigated high-frequency thermal detection using ThermoDynamic Imaging (TD-Imaging™), a laser-scanning thermoreflectance technique, together with radio-frequency lock-in thermography (RF-LIT). In this paper, we report the localization of an open-like high-resistance defect in a 3D flash memory device. The defect was not detected by conventional LIT at 500 Hz, whereas RF-LIT and TD-Imaging revealed thermal responses under high-frequency excitation. TD-Imaging further enabled separation of a line-shaped signal along the WL direction and a localized spot-like signal near the estimated defect location. By controlling the modulation frequency, duty cycle, and reference trigger condition, we show that the localized signal is likely associated with transient Joule heating induced by capacitive coupling. These results indicate that TD-Imaging is useful for localizing open-like high-resistance defects and for interpreting their thermal response mechanisms.
Continued device scaling and three-dimensional integration in semiconductor devices have significantly increased the difficulty of fault localization. In particular, open-like high-resistance defects are difficult to detect using conventional low-frequency thermal analysis because only limited steady-state current flows through the defective path, resulting in weak heat generation. To address this challenge, we investigated high-frequency thermal detection using ThermoDynamic Imaging (TD-Imaging™), a laser-scanning thermoreflectance technique, together with radio-frequency lock-in thermography (RF-LIT). In this paper, we report the localization of an open-like high-resistance defect in a 3D flash memory device. The defect was not detected by conventional LIT at 500 Hz, whereas RF-LIT and TD-Imaging revealed thermal responses under high-frequency excitation. TD-Imaging further enabled separation of a line-shaped signal along the WL direction and a localized spot-like signal near the estimated defect location. By controlling the modulation frequency, duty cycle, and reference trigger condition, we show that the localized signal is likely associated with transient Joule heating induced by capacitive coupling. These results indicate that TD-Imaging is useful for localizing open-like high-resistance defects and for interpreting their thermal response mechanisms.