Patent Document ID: 4870344
Application ID: 06729756
Patent Status: 1

Claim One:
1. An improved method to be used for inspecting objects such as integrated circuits, or other objects, where the object is irradiated by means of an electron beam of an electron microscope and where a detector is caused to detect electrons emitted from the object said object having a voltage level property, to determine a voltage level property of the object in at least one point which is generated by said irradiation, and to provide an output signal corresponding thereto, the improvement being characterized in that the points (nodes) on the object (16) to be inspected, in a first step, are allotted coordinates (x'.sub.i, y'.sub.i) in a coordinate system (x' - y') related to the object; the second step being that identification points on the object are determined for the object being inspected, these identification points also being allotted coordinates (x'.sub.i, y'.sub.i); the third step being that the object (16) is placed in an electron-microscope type device (1); the fourth step being that the position of the coordinate system x' - y' in relation to a coordinate system x - y related to the electron microscope (1) is determined by determining the position of the identification points relative to the coordinate system x - y; the fifth step being that the electron beam (7) of the electron microscope is then deflected into alignment with and irradiates said points (nodes) in a successive order, voltage being applied to said object upon inspection of each of the selected points (nodes); the next step being that the output signal obtained from the detector (4) upon irradiation of each of the selected points (nodes) is compared with the voltage level to the associated irradiated node; and using a data processor (15) to effect a coordinated transformation from the coordinate system x' - y' to the coordinate system x - y, whereafter the data processor (15) is caused to control and move the electron beam (7) to the selected points (nodes) to be inspected.