Method and apparatus for the generation of distortion-free images with electron microscope
AssigneeSiemens Aktiengesellschaft
InventorEduard Hieke
Life of this patent
Estimating the term…
Abstract
A specimen to be analyzed under an electron microscope is oriented at an inclined angle relative to a plane normal to the beam. The beam is deflected to form a scanning raster to scan the specimen, and the raster and specimen are each rotated independently about the axis of the beam, to produce an image of the inclined specimen in which orthogonal lines in the sample are represented by orthogonal lines in the image. A microprocessor is employed for rotating the scanning raster relative to the specimen in accordance with its angle of inclination, the effective focal length of the electron lens, the primary beam voltage of the electron beam, and the current flowing through the condenser lens.
Claims10
A method for the production of undistorted images of an inclined specimen in scanning electron microscope comprising the steps of rotating said specimen about the axis of the scanning beam until the x.sub.2 -direction in which the beam is deflected is aligned with the x.sub.1 -direction of the specimen, rotating the scanning raster of said scanning beam in the same direction through an angle .phi. until the angle between the x.sub.2 and the x.sub.1 directions is equal to the angle between the y.sub.2 -direction of said beam and the y.sub.1 -direction of said specimen, said angle .phi. being calculated from the angle of inclination of said specimen and the distance between said specimen and said microscope, and rotating said specimen back until the x.sub.1 -direction becomes aligned with the x.sub.2 -direction and the y.sub.1 -direction becomes aligned with the y.sub.2 -direction.
A method for the production of undistorted images of an inclined specimen in a scanning electron microscope comprising the steps of rotating the scanning raster of the scanning beam through an angle calculated from the angle of inclination and the working distance between said specimen and said microscope, and rotating said specimen until the scanning line direction and the direction of advance of scanning become aligned with two generally orthogonal directions on the surface of said specimen.
Apparatus for the production of distortion-free SEM pictures including a scanning electron microscope having a deflection system and an electron lens, means for supporting a specimen at an angle inclined to a plane normal to the scanning beam, means for producing a first signal representative of the angle of inclination, means for producing a second signal representative of the working distance between said specimen and said microscope, a control unit connected to receive said first and second signals, said control unit producing a control signal in accordance with an empirical relationship between the representations of said first and second signals, a raster rotation unit connected with said control unit and responsive to said control signal, said raster rotation unit being connected with said deflection system for rotating the raster of said scanning beam in response to said control signal.
Dependencies are inferred from the claim text.