Patent ID: 10901391

Abstract:
A method includes controlling a multi-scanning electron microscope, mSEM, to capture a first image of a wafer attached to a motorized handling stage while the motorized handling stage is in a first position. The first image includes at least a part of a notch of the wafer. The method also includes determining a radial axis of the wafer based on the first image, and controlling the motorized handling stage to shift the wafer along the radial axis by half a diameter of the wafer so that the motorized handling stage is in a second position. The method further includes controlling the mSEM to capture a second image of the wafer while the motorized handling stage is in the second position. The second image includes wafer structures. In addition, the method includes determining a reference position of the wafer based on a structure recognition of the wafer structures of the second image, and registering a wafer coordinate system of the wafer to a stage coordinate system of the motorized handling stage based on the reference position and the radial axis.