Nondestructive Fault Localization of Semiconductor Devices with Ultrasound Heating

As a conventional alternative, the IR-OBIRCH method is widely used to localize faults in semiconductor devices. In the IR-OBIRCH, the faults are localized by observing current changes induced by laser heating. Since the mold resin is not optically transparent and it disturbs the propagation of laser, the IR-OBIRCH method often requires a decapsulation of mold resin prior to the localization of the faults. The engineers of semiconductor devices call for a new alternative without need for the decapsulation which can find out where the circuit was broken down by an overvoltage. The authors developed the SOBIRCH method as an alternative without need for the decapsulation of mold resin. Today, semiconductor devices are in a trend of having a structure of stacked LSI chips by three-dimensional integration technology. By using a sample with simplified stacked structure of three-dimensional integration, this report suggested a possibility that the ultrasound resonance improves the sensitivity of SOBIRCH in cases of three-dimensional integrated semiconductor devices having a stacked structure.