Patent ID: 7067335

Claim:
A method of inspecting a test structure, comprising: initially scanning two or more initial portions of the test structure with a charged particle beam to image the initial portions and determine whether there is a defect present within a plurality of potential defect portions that have different locations than the initial portions based on whether there is an unexpected pattern of one or more intensity levels within the imaged initial portions, wherein the potential defect portions are not scanned by the particle beam during the initial scanning; and when the initial scanning results in a determination that a defect is present in one or more of the potential defect portions, sequentially stepping to one or more of the potential defect portions of the test structure and scanning the one or more potential defect portions of the test structure with a charged particle beam to thereby image the one or more potential defect portions and locate the defect, wherein the defect is located when an unexpected pattern of one or more intensity levels are present within a one of the imaged potential defect portions.