This paper provides an innovative root cause failure analysis method that combines multiple failure analysis (FA) techniques to narrow down and expose the shorting location and allow the material analysis of the shorting defect. It begins with a basic electrical testing to narrow down shorting metal layers, then utilizing mechanical lapping to expose over coat layers. This is followed by optical beam induced resistance change imaging to further narrow down the shorting location. Scanning electron microscopy and optical imaging are used together with focused ion beam milling to slice and view through the potential shorting area until the shorting defect is exposed. Finally, transmission electron microscopy (TEM) sample is prepared, and TEM analysis is carried out to pin point the root cause of the shorting. This method has been demonstrated successfully on Western Digital inter-metal layers shorting FA.