Patent ID: 9000366
Filing Date: 2015-04-07
Classification: H01J

Abstract:
1. An apparatus for measuring a displacement, comprising: an electron beam source for emitting an electron beam; a converging lens for converging the electron beam emitted from the electron beam source; a deflector for deflecting the electron beam converged by the converging lens; an objective lens for converging, scanning and irradiating the electron beam deflected by the deflector onto a surface of a sample; a sample stage for mounting the sample thereon and moving the sample in a plane; a detector for detecting secondary electrons emanated from the sample by irradiating the sample with the electron beam; an image forming unit that forms an image of the sample, based upon a detection signal corresponding to the secondary electrons emanated from the sample and detected by the detector; a control unit for controlling the electron beam source, the converging lens, the deflector, the objective lens, the sample stage, the detector, and the image forming unit; a computer that cooperates with the control unit and calculates the displacement between a plurality of patterns formed in different pattern-forming steps, wherein the calculation is based on a combination of a displacement amount between the plurality of patterns calculated from the sample image formed by the image forming unit and a displacement amount calculated from separately entered height information of the patterns formed in the different pattern-forming steps and information supplied from the control unit; and a data recorder for recording the displacement between the patterns, calculated by the computer.