Abstract: Herein are described layouts of test structures and scanning methodologies that allow large probe currents to be used so as to allow the detection of resistive defects with a resistance lower than 1 M? while at the same time allowing a sufficient degree of localization to be obtained for root cause failure analysis. The detection of resistances lower than 1 M? nominally requires a probe current greater than 1 micro ampere for detection on an electron beam inspection system.

Abstract: A method for electrically testing a wafer that includes: receiving a wafer having a first layer that is at least partly conductive and a second layer formed over the first layer, following production of openings in the second layer; directing towards the wafer a first set of beams of charged particles that are oriented at a first set of angles in relation to the wafer, whereas each angel of the first set of angles deviates substantially from normal, so as to pre-charge an area of the second layer without substantially pre-charging the first layer; scanning the area of the wafer by a second set of beams of charged particles that are oriented at a second set of angles in relation to the wafer, and collecting charged particles scattered from the area wafer.

Abstract: System and a method for electrically testing a semiconductor wafer, the method including: (a) scanning a charged particle beam along at least one scan line while maintaining an electrode located at a vicinity of the wafer at a first voltage that differs from a voltage level of a first scanned portion of the wafer, and collecting charged particles scattered from the first scanned portion; (b) scanning a charged particle beam along at least one other scan line while maintaining the electrode at a second voltage that differs from a voltage level of a second scanned portion such as to control a charging state of at least an area that comprises the first and second scanned portions; and (c) repeating the scanning stages until a predefined section of the wafer is scanned.