Scanning Capacitance Microscopy (SCM) has been extensively used for identifying doping issues in semiconductor failure analysis. In this paper, the root causes of two recent problems -- bipolar beta loss and CMOS power leakage -- were verified using SCM images. Another localization method, layer-by-layer circuit repair with IROBIRCH detection, was also utilized to locate possible defects. The resulting failure mechanism for bipolar beta loss is illustrated with a schematic cross section, which shows the leakage path from the emitter to the base. In the case of CMOS power leakage, the abnormal implantation of the Pwell region was identified with the Plane view SCM image.

The introduction of p+ implanted areas at the drain side of source-drain-gate salicide-blocked electro-static discharge (ESD) protection diodes resulted in a better ESD robustness, however at the expense of increased leakage currents in up to 40% of the 90nm technology test structures. Leaky devices are found to be randomly distributed across a wafer. The leakage current exhibits only weak temperature dependence and is linearly increasing with the p-implanted area. Photoemission microscopy revealed spots located exclusively in the p+ implanted areas. TEM imaging visualized, that the leakage path is caused by dislocations, reaching from the silicon surface through the p+n junction zone into the substrate. Based on these results and the implant conditions, a theory of dislocation formation was postulated and countermeasures had been defined.