Electric force microscopy as a probe of active and passive elements of integrated circuits

Integrated circuit (IC) device structures and metal interconnects have been investigated with atomic force microscopy (AFM). Tapping mode AFM was used to acquire topographical data. The focus of this paper is on the electrostatic interaction between a metallized AFM tip and the sample surface in noncontact mode. By varying the tip potential to minimize the electrostatic force between the tip and the surface, we were able to quantitatively probe voltages in metal interconnects and planar resistors, as well as image pn junctions and trapped charges.