A series of power supply line controller failures at Analog Devices Incorporated (ADI) exhibited abnormal output voltage and quiescent current symptoms. Our failure analysis revealed a gate-to-drain/source tungsten spur defect, which required a sophisticated multi-step detection process. The investigation combined several advanced techniques: light emission microscopy (LEM) and optical beam induced resistance change (OBIRCH) identified the failing circuit, passive voltage contrast (PVC) located the affected transistor, and nanoprobing with electron beam induced resistance change (EBIRCh) pinpointed the gate-to-source/drain leakage location. Focused ion beam (FIB) cross-sectioning proved crucial for physical analysis, as conventional chemical deprocessing would have destroyed the tungsten spur and potentially misidentified the defect as electro-static discharge damage. Transmission electron microscopy confirmed the spur's composition as tungsten, and subsequent fabrication investigation traced the root cause to a titanium nitride barrier breach at the contact bottom, occurring where contacts intersect with spacer nitride. The issue was resolved through critical dimension tightening at the fabrication site.

Integrated capacitors use metal plates such as in Metal-Insulator-Metal (MIM) and Metal-Oxide-Metal (MOM) capacitors while Polysilicon and Silicon (Si) substrate for metal-oxide-semiconductor (MOS) capacitors. Three major challenges and solutions were discussed in this technical paper. First, the failure site localization of a subtle defect in the capacitor plates. To determine the specific location of the defect site, Electron Beam Induced Current (EBIC) analysis was performed while the part was biased using a nano-probe set-up under Scanning Electron Microscopy (SEM) environment. Second, Failure Mechanism contentions between Electrically Induced Physical Damage (EIPD) or Fabrication process defect particularly, for damage site that is not at the edge of the capacitor and without obvious manifestations of Fabrication process anomalies such as bulging, void, unetched material or shifts in the planarity of the die layers. To further understand the defect site, Scanning Transmission Electron Microscopy (STEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS) were utilized to obtain high magnification imaging and elemental area mapping. Third, misled conclusion to be an EIPD site manifested by burnt and reflowed metallization. The EIPD site was only a secondary effect of a capacitor dielectric breakdown. This has been uncovered after understanding the circuit connectivity, inspections of the capacitors connected to the EIPD site, fault isolation and further physical failure analysis were performed. As results of the Failure Analysis (FA), Customer and Analog Devices Incorporated (ADI) manufacturing hold lots were accurately dispositioned and related corrective actions were precisely identified and implemented.