Failure analysis of plastic encapsulated MOS component from chip-section

Abstract

With the development of IC manufacturing industry, plastic encapsulated MOS components have been widely applied. Since higher performance requirement from users, the research on the reliability of plastic encapsulated MOS components is especially important. Through researching the common failure mechanism of plastic encapsulated MOS component, the physical and chemical processes of each failure mechanism are analyzed. In addition, some researches on the relationship among EOS (Electrical Over Stress), EM(Electro-migration) and ESD(Electrostatic discharge) have been completed. By study about the methods of failure analysis of plastic encapsulated MOS component, SAM (Scanning Acoustic Microscope) and SEM(Scanning Electron Microscope) are identified as the most important methods in failure analysis. According to the achievement of these researches, the procedure of failure analysis has been optimized by adding microscopy sample preparation. This improvement makes the analysis in chip surface extend to chip-section. In the case study, with this new procedure, a plastic encapsulated MOSFET has been analyzed. As a result, this failure is caused by the source-drain breakdown. Combining with the mechanism of EOS and EM, the direction of current in PN junction which is breakdown has been identified.