Short High Voltage Stress for Design-to-Process Characterization

摘要

We showed that the behavior of many units is the same as single unit behavior, and the behavior of a single unit is the same as single transistor behavior. Therefore, the weakest place in the product was localized just on single units, by means of short time stress at elevated voltage. At that weakest place, gate oxide of transistors had maximum damage by process charging because of a specific design configuration. Units with typical and abnormal slopes were characterized in an emission microscope in static state. The numbers of emission sources were detected and the correlation with the abnormality of the slope was obtained. Typical BI showed the reduced reliability of abnormal slope units, and FA of BI failures showed that the failure and the emission points locations are the same. This is the first time that we have applied accelerated Vcc voltage stress in static mode to typical units. The stress resulted in the appearance of the same emission points and change in the slope (similar to the results for abnormal slope units). This emission location indicates the weak points in the design-to-process interaction. Proposed fast stress enables the detection of design/manufacturing potential problems in a very short time (in comparison to hundreds of hours of typical BI stress). We propose to perform FA analytical/imaging analysis of new products in order to obtain better electrical characterization of weak points that are the result of problems in the design-to- process interaction. We also propose to implement this method for reliability characterization, low yield analysis and for process monitoring.