Patent ID: 7198963

Claim:
A method of inspecting defects in a semiconductor voltage contrast test structure suitable for voltage contrast inspection, the method comprising: along a first direction, moving a charged particle beam tool with respect to the voltage contrast test structure to a first area of the voltage contrast test structure so that the first area is within the charged particle beam tool's field of view to thereby determine whether there is a defect present within the voltage contrast test structure; when a defect is determined to be present selecting a substructure of the voltage contrast test structure, in which the defect is located, based on an image of the first area obtained by the charged particle beam tool; when a substructure has been selected repeatedly stepping the same charged particle beam tool, with respect to the voltage contrast test structure, across the selected substructure and along the same first direction with respect to the voltage contrast test structure so that at each step a next area of the substructure is within the charged particle beam tool's field of view until the defect is located within a particular next area of the substructure; and after the defect is located, using the same charged particle beam tool to generate a high resolution image of the defect whereby the image can be used to classify the defect.