JPH0243092Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of an electron beam apparatus equipped with an electromagnetic field of view moving means and a means for moving the field of view by moving a sample stage.

[Prior Art] In an electron beam device such as an electron microscope, the observation field of view can be moved by either moving the stage on which the sample is placed, or by electromagnetically deflecting the electron beam. However, moving the field of view by electromagnetically deflecting the electron beam can be done in a shorter time because no mechanical drive is required. Therefore, when the field of view must be moved many times in order to find a desired position on the sample to observe, the field of view movement by electromagnetic deflection is advantageous. However, the image obtained by moving the field of view by electromagnetic deflection is inferior in image quality because it is an image obtained by irradiation with an electron beam off the optical axis of the electron optical system. Therefore, in electron microscopes and the like, it is common practice to mechanically move the sample stage to change the field of view.

In conventional apparatuses, the field of view movement of the specimen stage is often performed by moving the specimen stage while observing a fluorescent plate provided in an observation chamber inside the lens barrel by looking into it from outside the lens barrel. Therefore, the operation for moving the sample stage is performed by, for example, manually operating the operation buttons provided on the operation console.

[Problems to be solved by the invention] In such a conventional device, if you accidentally press the operation button in a direction different from the direction of movement of the field of view, the sample stage will move in a direction different from the direction of movement of the desired field of view. It immediately moves to . In such a case, even if you release your hand from the operation button immediately after that, the sample stage will not stop immediately due to its inertia and will move to a field of view that is not the desired direction.
You may temporarily lose sight of the field of view you are trying to observe. SUMMARY OF THE INVENTION An object of the present invention is to provide an electron beam device that eliminates the above-mentioned drawbacks and prevents the user from losing sight of the field of view due to erroneous operation.

[Means for solving the problem] The configuration of the present invention includes an electromagnetic field moving means for moving the field of view by electromagnetic deflection, and a mechanical field of view moving means for moving the field of view by moving the sample stage. An apparatus for obtaining a sample image by electron beam irradiation, comprising: means for instructing movement of the field of view; and means for operating the electromagnetic field of view movement means when movement of the field of view is instructed by the instruction means. and means for moving the visual field by the mechanical visual field moving means instead of moving the visual field by the electromagnetic visual field moving means when the visual field movement is instructed to continue after a certain period of time has elapsed from the visual field movement instruction. It is characterized by having the following.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a configuration diagram of an embodiment of the device of the present invention.
In the figure, 1 is an electron gun, 2 is a focusing lens for focusing the electron beam 3 from the electron gun 1, 4 is a deflection coil for deflecting the electron beam 3 in the X direction and Y direction, 5 is an objective lens, 7 is a sample stage on which the sample 6 is placed. This sample stage 7 is powered by a pulse motor 8X.
and 8Y allows movement in the X and Y directions. 9 is a motor drive circuit, 10
are deflection coil power supplies, each connected to the control unit 11 and supplied with a control signal. 12 is the control unit 11
An operation console connected to the console includes, for example, operation buttons 12a and 12b for moving the sample stage in the X-axis direction and operation buttons for moving the sample stage in the Y-axis direction via the control unit 11. 12c and 12d are provided. Here, the electron beam transmitted through the sample 6 is displayed as a transmitted image on a fluorescent plate 15 by an intermediate lens 13 and a projection lens 14.

In the device configured as described above, for example, +
When moving the field of view in the X-axis direction, the user presses the operation button 12a while observing the fluorescent plate 15 by looking into it from outside the lens barrel. By the way, when these operation buttons 12a, 12b, 12c, and 12d are pressed (ON state), they output a high-level signal H as shown in FIG. state), a low level L signal is output. Therefore, when moving the field of view in the +X-axis direction, for example, when the operation button 12a is pressed, a start signal S shown in FIG.
When the start signal S from the console 12 is input to the control unit 11, the control unit 11 starts the deflection coil power supply 10.
is controlled to supply the electromagnetic deflection signal shown in FIG. 2C to the deflection coil 4 for a time Δt. Due to this electromagnetic deflection signal, the field of view of the transmitted image projected onto the fluorescent plate 15 is moved by a time Δt in the +X-axis direction. This +X
The field of view of the transmitted image moving in the axial direction can be observed from outside the lens barrel. When a time ΔT, which is slightly longer than this time Δt, has elapsed, the control unit 11 supplies the motor control signal shown in FIG. move it. That is, when the operation button 12a is pressed, the field of view first moves by the time Δt in the +X-axis direction due to electromagnetic deflection. Then, after this time Δt has elapsed, the field of view movement due to electromagnetic deflection is set to 0, and after a time ΔT slightly longer than Δt has elapsed, the sample stage moves in the +X-axis direction and the field of view moves. Here, the time ΔT can be set arbitrarily, but about 1 to 2 seconds is convenient for observation, and the distance of visual field movement due to electromagnetic deflection is set to an appropriate value depending on the magnification.

By the way, in the above-mentioned example, when operating the operation button, if the operation button 12b for moving in the -X-axis direction is pressed by mistake, the field of view moves in the -X-axis direction due to electromagnetic deflection. Therefore, suppose that the operator who is observing the fluorescent plate 15 notices that he or she has made a mistake in button operation, and releases the operation button 12b at time _t1 in FIG. 2A. As a result, the output signal of the operation button 12b changes to low level L, and this signal causes the operation console 12 to
outputs an end signal E to the control section 11. Control part 1
1 determines that the end signal E is output within the time ΔT and stops driving the sample stage. Therefore, when the visual field movement due to electromagnetic deflection ends, the visual field returns to the one before pressing the button 12b.
Therefore, the number of corrections in the sample moving direction due to erroneous operations is reduced, making it easier to move the field of view.

In the above embodiment, the field of view is moved by the deflection coil over a period of Δt.
It may be moved multiple times within the time period Δt.

Further, in this embodiment, an example in which the present invention is applied to an electron microscope has been described, but the present invention can also be applied to a scanning electron microscope.

[Effect] As explained in detail above, according to the present invention, when the field of view is moved by the sample stage, movement of the field of view due to incorrect operation of the operation button is prevented. can be easily operated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a diagram illustrating each output signal of the embodiment shown in FIG. 1: Electron gun, 2: Focusing lens, 3: Electron beam,
4: Deflection coil, 5: Objective lens, 6: Sample,
7: Sample stage, 8X, 8Y: Motor, 9: Motor drive circuit, 10: Deflection coil power supply, 11: Control unit, 12: Operation console, 13: Intermediate lens, 14:
Projection lens, 15: Fluorescent plate.

Claims (1)

[Scope of utility model registration request] An apparatus for obtaining a sample image by electron beam irradiation, which is equipped with an electromagnetic field moving means for moving the field of view by electromagnetic deflection and a mechanical field moving means for moving the field of view by moving the sample stage. means for instructing movement; means for operating the electromagnetic visual field moving means when movement of the visual field is instructed by the instruction means; and continued movement of the visual field after a certain period of time has elapsed from the instruction to move the visual field. An electron beam apparatus characterized by comprising means for moving the field of view by the mechanical field of view moving means instead of moving the field of view by the electromagnetic field of view moving means when the field of view is instructed.