Electron beam inspection system and inspection method and method of manufacturing devices using the system
View Patent ↗An electron beam inspection system of the image projection type includes a primary electron optical system for shaping an electron beam emitted from an electron gun into a rectangular configuration and applying the shaped electron beam to a sample surface to be inspected. A secondary electron optical system converges secondary electrons emitted from the sample. A detector converts the converged secondary electrons into an optical image through a fluorescent screen and focuses the image to a line sensor. A controller controls the charge transfer time of the line sensor at which the picked-up line image is transferred between each pair of adjacent pixel rows provided in the line sensor in association with the moving speed of a stage for moving the sample.
1. An electron beam inspection system comprising:
an electron irradiation gun for irradiating a primary electron beam to a surface of a sample;
stage for supporting and moving the sample in a direction;
a secondary optical system for magnifying and projecting secondary electrons generated from the sample by irradiating the primary electron beam to form an image of the surface of the sample;
a TDI (Time Delay Integration)-CCD (Charged Coupled Device) for detecting the secondary electrons and integrating electric charges converted from the detected secondary electrons in a surface array direction of the TDI-CCD; and
a magnetic lens for rotating an image formed by the secondary electrons passing the magnetic lens such that a scanning direction of the sample as scanned by moving the stage coincides with an integration direction for integrating the electric charges in the surface array direction of the TDI-CCD by controlling the intensity of magnetic field which is produced by the magnetic lens and applied to the secondary electrons.
2. An electron beam inspection system according to claim 1 , wherein the magnetic lens is positioned between a lens in a final stage of the optical system and a microchannel plate placed in a preceding stage of the TDI-CCD.
3. An electron beam inspection system according to claim 2 , wherein the magnetic lens is disposed at a crossover position closest to the microchannel plate.
4. An electron beam inspection system according to claim 1 , wherein the magnetic lens is disposed at an image-formation position closest to a final-stage lens of the optical system on a side of the final-stage lens remote from the microchannel plate.
5. A device fabrication method using the electron beam inspection system according to claim 1 .