JPH028356Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for displaying the deflection angle of an electron beam in an electron microscope or the like.

Observation of dark-field images has conventionally been performed using the following devices. That is, in Figure 1, 1
is an electron gun, and the electron beam from this electron gun 1 is focused by a focusing lens system 2 consisting of focusing lenses 2a and _2b to form an electron beam with good parallelism. The light is incident on a two-stage deflection system 3 consisting of D _1y and second-stage deflection coils D _2x and D _2y .
Deflection coils D _1x and D _2x are coils for deflecting the electron beam in the X direction, and D _1y and D _2y are coils for deflecting the electron beam in the Y direction, which is perpendicular to the X direction. The electron beam deflected by the two-stage deflection system enters the sample 4, and the image of the electron beam transmitted through the sample 4 is formed by an imaging lens system 8 consisting of objective, intermediate, and projection lenses 5, 6, and 7. and projected onto the fluorescent screen 9. 10x and 10y are deflection power supplies for supplying deflection currents to the deflection coils D _1x and D _1y , respectively; 11x and 11y are deflection power supplies for supplying deflection currents to the deflection coils D _2x and D _2y , respectively. be. Sx and Sy are potentiometers for changing the incident position of the electron beam EB in the X direction and in the Y direction perpendicular to the X direction while maintaining the incident angle of the electron beam EB on the sample 4 (this operation is hereinafter referred to as shift); Tx and Ty are potentiometers for changing the incident angle of the electron beam EB on the sample in the X and Y directions while maintaining the incident position on the sample (this operation is hereinafter referred to as tilting). The output signals from the potentiometers Sx and Sy are supplied to power supplies 10x and 10y, respectively, and the output signals from the potentiometers Tx and Ty are supplied to power supplies 11x and 11y, respectively. , 10y, so that the incident position does not change even when the incident angle is changed.

In such a configuration, when attempting to observe a dark-field image, for example, first operate the potentiometers Sx and Sy to move the irradiation position of the electron beam EB onto the sample 4 to an arbitrary position. After that, the electron beam EB is made to be incident on the sample 4 at an angle as shown in FIG. 1 by operating the potentiometers Tx and Ty. Therefore, out of the electron beams EB that have passed through the sample 4, the electron beams EB' that have proceeded in the optical axis direction are guided to an imaging lens system to obtain a dark field image on the fluorescent screen 9, but the conventional apparatus described above In this case, sample 4
Since it is not possible to display the angle of the electron beam incident on the sample, even if a dark field image is obtained, it is difficult to understand the correspondence between the image and the angle at which the electron beam was incident on the sample. Can not do it. or,
Even if the sample is known and you want to obtain a dark-field image when the electron beam is incident at a predetermined angle, the angle of incidence of the electron beam cannot be easily determined, so it is necessary to repeat trial and error to obtain a dark field image. The angle of incidence of the line must be set to a desired value, which is troublesome.

The present invention solves these conventional drawbacks, allows the electron beam to be immediately incident on the sample at a desired angle of incidence, and the obtained dark field image shows the angle at which the electron beam is incident on the sample. The object of the present invention is to provide an apparatus that allows one to easily determine whether an image has been obtained.

The present invention includes an electron gun, a focusing lens system for focusing an electron beam from the electron gun, and a system for deflecting the electron beam focused by the focusing lens system in an X direction and a Y direction perpendicular to the X direction. an X- and Y-direction deflector, an X- and Y-direction deflection power source for supplying a deflection current to the X- and Y-direction deflector, a sample to which an electron beam deflected by the deflector is irradiated, and the sample. In an apparatus equipped with an imaging lens system for forming an image of an electron beam that has passed through the a first display means consisting of;
a second display means comprising a large number of display elements arranged on a second straight line perpendicular to the first straight line to display the amount of deflection by the Y-direction deflector; means for lighting a display element of the first display means in accordance with the amount of deflection in the X direction based on a signal representing a deflection current supplied to the direction deflector; The present invention is characterized by comprising means for lighting up a display element of the second display means in accordance with the amount of deflection in the Y direction based on a signal representing a deflection current supplied to the directional deflector.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a diagram showing one embodiment of the present invention, and in FIG. 2, the same components as in FIG. 1 are given the same numbers. Unlike before, the output signals from potentiometers Tx and Ty are A.
The signal is supplied to linearity correction circuits 13x and 13y via -D converters 12x and 12y. Since the value of the deflection signal supplied to the deflection coil and the angle of the electron beam incident on the sample are not strictly proportional, the linearity correction circuits 13x and 13y convert the deflection signal into a signal proportional to the angle. It is a circuit. The output signals of the linearity correction circuits 13x and 13y are supplied to the drive circuit 14. The output signal of this drive circuit 14 is supplied to display element arrays 15x and 15y, which are composed of a large number of display elements arranged on the operation panel. The display element rows 15x and 15y are arranged orthogonally to each other, and
Scales 16x and 16y representing angles are provided along the display element rows 15x and 15y.

In such a configuration, the potentiometer
Since a deflection current proportional to the output signal value of the potentiometer Tx is supplied from the deflection power supply 11x to the deflection coil D _2x , the electron beam EB is tilted in the X direction by an angle proportional to the output signal value of the potentiometer Tx, and the sample 4 The signal from the potentiometer Tx is converted into a digital signal by an A-D converter 12x, and then sent to a linearity correction circuit 13x, which has a value proportional to the inclination angle θx of the electron beam EB in the X direction. After being converted into a signal, it is supplied to the drive circuit 14. The drive circuit 14 is the linearity correction circuit 1
In order to light up the display elements of the display element row 15x by a number proportional to the signal value supplied from the electron beam 3x, the number of elements on the display element row 15x is turned on by the number corresponding to the incident angle θx of the electron beam EB in the X direction. Note that when the signal value supplied to the drive circuit 14 is negative, the elements on the negative side of the display element array 15x (the left side of the intersection O between the element arrays 15x and 15y) are lit. In exactly the same way, power supply 1 is proportional to the output value of potentiometer Ty.
A deflection current is supplied to the deflection coil D _2y from 1y, but the signal corrected by the potentiometer 15y in the linearity correction circuit 13y is sent to the drive circuit 1.
4, the number of elements on the display element 15y is turned on by the action of the drive circuit 14, the number of which corresponds to the incident angle θy of the electron beam EB in the Y direction. Therefore,
For example, if θx is 4 degrees and θy is 2 degrees, the third
A display as shown in the figure is obtained, and by looking at this display, it can be understood that the electron beam EB is incident on the sample at an angle corresponding to the length of the vector A in the direction of the vector A.

It should be noted that the above-described embodiment is only one embodiment of the present invention, and many modifications can be made. For example, in the above-described embodiment, the number of elements whose length is proportional to the deflection angles θx and θy is lit, but only the elements at the end of the length may be lit.

As is clear from the above description, according to the device based on the present invention, the inclination angle of the electron beam incident on the sample can be determined with a simple configuration, and the electron beam can be immediately incident on the sample at a desired angle. At the same time, it is possible to know at what angle the electron beam was incident on the obtained dark-field image.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a conventional device, FIG. 2 is a diagram for showing an embodiment of the present invention, and FIG. 3 is a diagram for showing a state of display by a display element array. 1...Electron gun, 2...Focusing lens system, D _1x ,
D _1y , D _2x , D _2y ... Deflection coil, 4 ... Sample, 5
... Objective lens, 6 ... Intermediate lens, 7 ... Projection lens, 9 ... Fluorescent screen, 10x, 10y, 11
x, 11y...deflection power supply, Sx, Sy, Tx, Ty...
...Potentiometer, 12x, 12y...A-
D converter, 13x, 13y... linearity correction circuit, 14... drive circuit, 15x, 15y... display element row, 16x, 16y... scale.

Claims (1)

[Scope of utility model registration request] an electron gun, a focusing lens system for focusing the electron beam from the electron gun, and an a Y-direction deflector;
and X for supplying deflection current to the Y-direction deflector.
and a Y-direction deflection power supply, a sample irradiated with an electron beam deflected by the deflector, and an imaging lens system for imaging the electron beam transmitted through the sample, wherein the X-direction deflection a first display means comprising a plurality of display elements arranged on a first straight line for displaying the amount of deflection of the electron beam by the Y-direction deflector; a second display means consisting of a large number of display elements arranged on a second straight line orthogonal to the means for lighting a display element of the first display means in accordance with the amount of deflection in the X direction; An electron beam deflection angle display device for an electron microscope or the like, comprising means for lighting a display element of the second display means in accordance with the amount of deflection in the Y direction.