A test structure which includes alternating grounded and floating conductive lines may be used to test the formation of conductive features on an integrated circuit topography. During irradiation of the conductive lines from an electron source, the grounded conductive lines will appear darker than the floating conductive lines when the test structure is inspected. If a short occurs between the conductive lines, due to an extra material defect, the portion of the floating line in the vicinity of the defect will also appear darkened. If an open appears along a grounded line, the non-grounded portion of the grounded line will be glowing. The grounded conductive lines are preferably grounded through a depletion-mode transistor. By applying a voltage to the transistor, the grounded line may be disconnected from ground, allowing electrical testing of the test structure. The electrical testing may be used to validate the voltage contrast methodology, as well as determine the approximate size of defects formed on the test structure.