JPH08124510A - Sample stage drive for analyzer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sample stage driving device for an analyzer for performing elemental analysis of a sample, which is capable of easily moving a sample minutely. [Structure] The control means 4 controls the pulse from the trackball 2.
The sample stage 7 of the analyzer is driven via XY axis stepping motors 8 and 9 to drive the stage. Since the amount of drive of the sample stage is proportional to the amount of rotation of the trackball, it is easy to intuitively understand and the sample can be easily moved to the target position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer for performing elemental analysis and state analysis of a sample, particularly an electron beam microanalyzer, scanning electron microscope, photoelectron spectrometer, electron beam diffractometer, secondary ion mass spectrometer, etc. The present invention relates to a sample stage applied to an analyzer capable of local analysis.

[0002]

2. Description of the Related Art In an analyzer for irradiating a sample surface with an electron beam or X-ray and detecting secondary electrons, X-rays, Auger electrons, etc. from the sample to observe the sample surface or perform elemental analysis. , On the sample stage with two XY axes to move in the sample surface to change or determine the analysis position of the sample, or a drive axis with three axes including the Z axis for adjusting the sample height. Place the sample. The operator searches for the analysis position while observing the sample image displayed on a display device such as an optical microscope or CRT for observing the sample surface, and the desired analysis position on the sample surface is irradiated with an electron beam or X-ray. Move the sample stage to match the position. As a method of driving this sample stage, an operator directly turns each drive shaft by using a hand, or when the drive is performed through a control device, particularly when driving in the XY plane, a lever called a joystick is used. There has been a method in which the operator tilts in a desired direction to drive an XY axis motor in that direction to move the sample stage.

[0003]

The operation of the sample stage XY axes by the joystick is only necessary to tilt the lever in the desired direction, which is intuitively easy to understand. However, due to the internal structure of the joystick, the joystick controls the drive speed of the stage in proportion to the tilt angle of the lever, and it was not easy to operate when a small amount of movement was required. . That is,
For example, if the analysis position is at the edge of the visual field of the sample surface observation optical microscope and it is brought to the center of the visual field of the optical microscope, the tilt angle of the lever is proportional to the moving speed of the stage. It was very difficult to stop the stage at the target position because it was difficult to intuitively grasp the relationship with the quantity itself.

Since the joystick output is an analog output, an analog / pulse conversion circuit is required to use it as a drive pulse for the stepping motor.
The circuit configuration becomes complicated, which in turn increases the manufacturing cost.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a sample stage drive device of an analyzer is provided with a sample stage having drive shafts in at least two directions, and a drive stage for rotating the drive shafts. Of the stepping motor, a drive circuit of the stepping motor, and a trackball for instructing the movement amount and the movement direction of the sample stage, respectively, and the stepping motor drive circuit is controlled by the output signal of the trackball. It was decided to.

[0006]

The trackball has a sphere-shaped operation unit, and is an apparatus for generating a drive pulse of XY 2-axis by the operator rotating the sphere, so that the drive pulse is transmitted through the interface to the XY-axis of the sample stage. To drive the stage by applying the same to the stepping motor drive circuit. Since the amount of drive of the sample stage is proportional to the number of pulsed signals given to the stepping motor, that is, the amount of rotation of the trackball, the amount of movement of the sample stage is exactly the same as the amount the operator rotates the trackball. Since it is intuitively easy to understand, it is very easy to move the sample to the target position.

Since the output of the trackball is pulse-shaped from the beginning, all control systems can be constructed by digital circuits, and an extra circuit configuration such as an analog / pulse conversion circuit is unnecessary.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention in which an analyzer is an electron beam microanalyzer. First, the operation of a known electron beam microanalyzer will be briefly described. When the sample 22 is irradiated with the electron beam 21, X-rays 24 are emitted from the sample 22, and the X-rays are spectrally detected by the X-ray spectroscope 25 to perform elemental analysis of the sample. Secondary electrons are also emitted from the sample 22, which is detected by the secondary electron detector 27, and the signal is displayed on the CRT 28 in synchronization with the scanning of the electron beam 21 on the sample surface. A secondary electron image of is obtained on the CRT 28. Further, as a means for observing the sample surface, an optical microscope 2
3 is also prepared, and the optical axis is adjusted so that the center of the visual field of this optical microscope is at the position where the electron beam strikes. In FIG. 1, an electron gun for generating an electron beam, an electron lens for converging the electron beam, a deflector for scanning the electron beam on the sample surface, a vacuum exhaust device for evacuating the inside of the device, Illustration of a control device for controlling each part, an external computer for controlling the entire device, etc. is omitted.

The sample 22 is mounted on the sample stage 7 having three XYZ drive axes. Of the three axes of the sample stage, X and Y are mutually orthogonal axes that drive the sample in a horizontal plane, and the Z axis is an axis that drives the sample in the vertical direction.
Since the analysis surface of the sample 22 is mounted on the sample stage so as to be almost horizontal, after the sample surface is adjusted to the analysis height by Z-axis drive, the position to be analyzed in the sample surface is appropriately driven by driving the XY axes appropriately. You can search and move to the center of the visual field of the optical microscope. The XYZ axes of the sample stage are configured to be driven by an X-axis stepping motor 8, a Y-axis stepping motor 9, and a Z-axis stepping motor 10, respectively.

A track ball 2 and a rotary encoder 3 are prepared on the sample stage operation panel 1 as a man-machine interface for the operator to move the sample. The trackball 2 is the X axis and Y of the sample stage.
The axis is driven to move the sample in the analysis plane, and the rotary encoder 3 is used to drive the Z axis of the sample stage to adjust the height of the sample plane. FIG. 2 shows an example of the appearance of the sample stage operation panel.

The trackball 2 has a sphere-shaped operating portion, and the sphere can be rotated in all directions such as front-back, left-right and diagonal. When the sphere is rotated to the left and right, a pulse for driving the X axis of the sample stage is generated to drive the X axis. When the sphere is rotated to the right, the sample moves to the right and the sphere is moved. When rotated to the left, the sample moves to the left. When the sphere is rotated in the front-back direction, a pulse for driving the Y-axis of the sample stage is generated to drive the Y-axis. When the sphere is rotated in the front direction, the sample moves in the front direction and the sphere is moved. When the sample is rotated in the front direction, the sample moves in the front direction. When the sphere is rotated in an oblique direction, both X-axis and Y-axis pulses are generated and both XY axes are driven simultaneously.

The knob 29 attached to the rotary encoder 3 can rotate clockwise and counterclockwise, and the rotation generates a pulse for driving the Z axis of the sample stage to drive the Z axis. That is, when the knob 29 is rotated clockwise, the sample rises, and when the knob 29 is rotated counterclockwise, the sample descends.

The two-phase pulse signals of the X-axis signal and the Y-axis signal from the trackball 2 and the Z-axis signal from the rotary encoder 3 are driven by the interface 5 in the controller 4, respectively. Is converted into a direction signal and input to the driver 6 which is a drive circuit of the stepping motor. The stepping motor driver 6 determines the X-axis stepping motor 8 in accordance with the number of input pulses.
Y-axis stepping motor 9, Z-axis stepping motor 1
Drive 0 respectively. By doing so, the sample moves by an amount proportional to the amount of rotation of the trackball or the rotary encoder operated by the operation panel. The output pulse from the interface 5 is XY
It is also input to the address counter 11 which stores the current position information of each Z axis, and the current position information of the sample stage 7 is constantly updated.

In converting the pulse generated by the trackball or the rotary encoder into the pulse given to the stepping motor driver 6, the number may be adjusted by applying an appropriate coefficient. By doing so, it is possible to change the relationship between the amount of rotation of the trackball or the like and the amount of movement of the sample while maintaining proportionality. For example, if the sensitivity of the trackball is changed between changing the sample position while observing the optical microscope and changing the sample position while observing the high-magnification secondary electron image, the operation becomes easier. As a means for changing the coefficient, a selection switch for selecting the sensitivity of a trackball or the like may be provided on the operation panel to give a signal to the controller 4, or a signal for changing the coefficient may be sent from an external control computer or the like to the controller. 4 may be given.

[0015]

When the stage is driven by applying the pulse from the trackball to the XY axis stepping motor of the sample stage through the control means, the driving amount of the sample stage is the number of pulse signals applied to the stepping motor. That is, since it is proportional to the amount of rotation of the trackball, the amount of movement of the sample stage perfectly matches the amount of rotation of the trackball by the operator, and it is easy to intuitively understand, so it is very easy to move the sample to the target position. Becomes

Particularly, when observing a high-magnification secondary electron image with a scanning electron microscope or an electron beam microanalyzer and when it is desired to move the sample by a very small amount, a slight rotation of the trackball can be performed accordingly. Since the sample stage also moves slightly, the operability is incomparably better than the conventional joystick. Also, the control system using the trackball has a simpler circuit configuration and can be constructed at a lower cost than the control system using the joystick.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 shows an embodiment of an operating unit of the present invention.

[Explanation of symbols]

1 ... Operation panel 2 ... Trackball 3 ... Rotary encoder 4 ... Controller 5 ... Interface 6 ... Stepping motor driver 7 ... Sample stage 8 ... X-axis stepping motor 9 ... Y-axis stepping motor 10 ... Z-axis stepping motor 11 ... Address counter 21 ... Electron beam 22 ... Sample 23 ... Optical microscope 24 ... X-ray 25 ... X-ray spectroscope 26 ... Secondary electron 27 ... Secondary electron detector 28 ... CRT 29 ... Knob

Claims (1)

[Claims] 1. A sample stage having drive shafts in at least two directions, separate stepping motors for rotationally driving the drive shafts, and a drive circuit for the stepping motors.
A sample stage driving device of an analyzer, comprising: a trackball for instructing a moving amount and a moving direction of the sample stage, and controlling the stepping motor driving circuit by an output signal of the trackball.