Voltage Contrast like Imaging of N-Wells

Voltage contrast like imaging of n-wells in a grounded psubstrate is presented as a new method for assisting FIB microsurgery from the backside of the die. The initial, transient contrast is used for endpointing in the trenching process. It is made permanent by a spontaneous XeF2 etch followed by the deposition of a SiOx layer. Applications include direct CAD – FIB alignment and visualization of the wells for failure analysis.