When the orientation angle becomes 30°, as can be seen from Figure at low electron wind intensities, the edge-void transforms into a kink-shape step at the surface -having a steep edge on the windward side- which may multiply on the windward side while the wave package all together drifting towards the cathode end. At moderate and high electron wind intensities, a hip or hillock forms in front of traveling edge-void, which eventually over hangs and traps the edge-void as such that the edge void becomes an interior void. This very unusual process is more pronounce and fast when the diffusion anisotropy coefficient is low, about A ≤5 . This self-trapped void becomes wedge shape and drags towards the cathode end. During the traveling period, it may or may not touch the opposite edge of the interconnect dependence upon the aspect ratio and the size of the initial Gaussian edge void with respect to the line width.