Failure Analysis of Au-Al Wire Bonding to MOSFETs

Abstract

Abstract. The gold and aluminum (Au-Al) wire bonding is used to realize interconnection for semiconductor devices. But, sometimes, the failure of Au-Al bond wire exists. In this paper, the failure influence factors of Au-Al bonding to Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) were discussed. Then the wire bond failure analysis of MOSFETs were researched. And bond strength analysis, microscopic examination, scanning electron microscopy (SEM) examination and energy dispersive spectrometer (EDS) analysis, which belongs to the details of all the tests, were completed combined with an application example of MOSFETs. The results demonstrated that the high temperature and the stain in the device lead to the failure of MOSFETs. The temperature is too high to make voids named Kirkendall holes on the interface of Au-Al bonding. And the pollution influenced the materials to cause the bond wire off the substrate. It was suggested that the key parameter, that it to say, the temperature and the pollution like carbon oxygen compound should be strictly controlled to improve the reliability of MOSFETs, especially in the high temperature storage and working conditions.