JP2007225407A - Electronic spectroscopic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a predetermined photoelectronic spectroscopic measurement even if a sample is inclined. <P>SOLUTION: This electronic spectroscopic device is provided with a control unit 21 for operating a sample stage control unit 31, a lens stage control unit 32, a visual field restricting iris control unit 33, an angle restricting iris control unit 34 and a power supply unit 20 in connection with each other and a memory 35 for storing a position where an image forming lens 9 does not interfere with a sample stage 5 with respect to the angle of inclination of the sample stage 5, the opening diameter of a visual field restricting iris 16 to the position of the image forming lens 9, the opening diameter of an angle restricting iris 17, the applied voltage to an electrostatic lens 15 and the supply current to the image forming lens 9. The position of the image forming lens 9 corresponding to the angle of inclination of the sample stage 5 and the opening diameter of the visual field restricting iris 16, the opening diameter of the angle restricting iris 17, the applied voltage to the electrostatic lens 15 and the supply current value to the image forming lens 9 capable of performing predetermined analysis with respect to the position of the image forming lens 9 are called out of the memory 35 to operate the respective units in connection with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

   The present invention relates to an electron spectrometer such as a photoelectron spectrometer.

A photoelectron spectrometer is an apparatus that irradiates a sample surface with X-rays, analyzes photoelectrons emitted from the sample by the irradiation with an electron spectrometer, and obtains an energy spectrum. By analyzing the obtained spectrum, It is possible to know surface elements and chemical states of the elements.
FIG. 1 shows a schematic example of such a photoelectron spectrometer.

  In the figure, reference numeral 1 denotes an analysis chamber, the interior of which is evacuated to a vacuum by an exhaust device 2.

  A sample 4 supported by a sample holder 3 is disposed in the center of the analysis chamber 1, and the sample holder 3 is placed on a sample stage 5. This sample stage is attached to the side wall of the analysis chamber 1, and can be moved in the three-dimensional (X, Y, Z) direction by adjusting the sample stage position adjusting mechanism 6, or the X axis or Y axis can be rotated. It can be tilted as.

  Reference numeral 7 denotes an X-ray source for photoelectron excitation, which is attached to the upper wall of the analysis chamber 1 so that the sample 4 can be irradiated with X-rays. Reference numeral 8 denotes a power source of the X-ray source.

  A magnetic imaging lens 9 is disposed below the sample 4 and is attached to the lens stage 10. This lens stage is attached to the side wall of the analysis chamber 1 and can be moved in the three-dimensional (X, Y, Z) direction by adjusting the lens stage position adjusting mechanism 11.

  An electron spectrometer 12 is attached to the upper lid of the analysis chamber 1. The electron spectrometer includes an input lens 13, an analyzer 14 for energy analysis of photoelectrons from the input lens, and a detector 15 for detecting photoelectrons selected by the analyzer.

  The input lens 13 has an electrostatic lens 15 for decelerating the collected photoelectrons and for focusing on the analyzer 14.

  The input lens 13 also has a field limiting aperture 16 for limiting a region for capturing photoelectrons generated on the surface of the sample 4 and a capturing angle of the photoelectrons that have passed through the field limiting aperture. An angle limiting diaphragm 17 is provided to reduce blur due to spherical aberration of the lens system and compensate the accuracy of the analysis region on the sample surface.

The field limiting diaphragm 16 is arranged so as to partition the inside of the input lens 13 so that the center of the opening K1 is positioned on the optical axis O of the input lens 13. For example, an iris diaphragm is used as the field limiting diaphragm 16, and the aperture diameter can be continuously changed by adjusting the aperture diameter adjusting mechanism 18.
The angle limiting diaphragm 17 is arranged so as to partition the cylinder of the input lens 13 so that the center of the opening K2 is positioned on the optical axis O of the input lens 13. For example, an iris diaphragm is used as the angle limiting diaphragm 17, and the opening diameter can be continuously changed by adjusting the opening diameter adjusting mechanism 19.

  A power unit 20 controls the current to the magnetic field imaging lens 9, the voltage to the electrostatic lens 15, the voltage to the analyzer 14, and the voltage to the detector 15.

  Reference numeral 21 denotes a control device that functions as a so-called central control device that generates a photoelectron spectrum based on a signal from the detector 15 and displays the photoelectron spectrum on the display device 22 or sends a command to the power supply unit 20. .

  When analyzing a sample in the apparatus having such a configuration, the operator adjusts the aperture diameter adjusting mechanism 18 to set the aperture diameter of the field limiting aperture 16 to a predetermined size optimum for the sample analysis at this time. Further, the aperture diameter adjusting mechanism 19 is adjusted so that the aperture diameter of the angle limiting diaphragm 17 is set to a predetermined size that reduces blurring caused by spherical aberration of the lens system.

  The degree of vacuum in the analysis chamber 1 is constantly monitored by the control device 21. When the degree of vacuum in the analysis chamber 1 enters a predetermined range, the control device 21 performs X-ray irradiation for irradiating the sample 4 with X-rays. A radiation irradiation command is sent to the X-ray source power supply 8. Further, the control device instructs each component (electrostatic lens 15, analyzer 14 and detector 15) of the electron spectrometer 12 to apply a predetermined voltage suitable for sample analysis at this time, and the magnetic field. A command for supplying a predetermined current suitable for sample analysis at this time to the mold imaging lens 9 is sent to the power supply unit 20.

  By such a command, a voltage is applied from the power supply unit 20 to the electrostatic lens 15 so that the photoelectrons from the sample 4 are decelerated by the electrostatic lens 15 and focused on the entrance slit of the analyzer 14. A current is supplied to the magnetic field type imaging lens 9 so that the photoelectrons from the sample 4 are focused on the aperture of the field limiting diaphragm 16 by the imaging lens.

  In such a state, X-rays are generated from the X-ray source 7 by the operation of the X-ray source power supply 8 in response to a command from the control device 21 and irradiated to the sample 4. Photoelectrons are emitted from the sample by the X-ray irradiation.

  The photoelectrons are focused on the field limiting aperture 16 by the magnetic field type imaging lens 9, and the photoelectrons that have passed through the aperture K1 of the field limiting aperture 16 and the aperture K2 of the angle limiting aperture 17 are decelerated and focused by the electrostatic lens 15. To the analyzer 14.

  The photoelectrons subjected to energy selection by the analyzer are detected by the detector 15. The detector converts the detected photoelectron signal into an electrical signal and outputs it.

The control device 21 generates a photoelectron spectrum based on the output signal and causes the display device 22 to display the photoelectron spectrum.
JP 2003-004676 A JP 2003-1887738 A JP 2002-214170 A

  In the photoelectron spectrometer, a magnetic field imaging lens 9 is disposed below the sample 4. The reason for the arrangement of the magnetic field type imaging lens 9 will be described below.

  When measuring a minute region of the sample 4 with the photoelectron spectrometer, if the measurement region on the sample is made smaller by the field limiting diaphragm 16, the sensitivity of photoelectrons from the sample 4 is reduced. Therefore, if the magnetic field type imaging lens 9 is arranged under the sample, it is possible to create a peak of the magnetic field distribution near the sample position, thereby reducing the aberration coefficient as a lens and enabling high spatial resolution. . If the excitation current of the magnetic field type imaging lens 9 is controlled so that the photoelectrons emitted from the sample are imaged on the field-limiting aperture, and the photoelectron capture angle is wide, the photoelectrons emitted from the sample 4 are emitted. More photoelectrons can be taken into the electrostatic lens 15, and as a result, more photoelectrons can be guided to the analyzer 14, and the sensitivity of photoelectrons from the sample 4 can be increased.

  In the sample analysis in the photoelectron spectrometer, there is a case where the sample is measured in a state where the sample is inclined at a high angle (eg, angle-resolved photoelectron spectroscopy). In such a case, it is necessary to adjust the sample stage position adjusting mechanism 6 so that the sample stage 5 is inclined with the X axis or the Y axis as the rotation axis.

  However, if the sample stage 5 is tilted at a high angle, there is a risk of colliding with the magnetic field type imaging lens 9 arranged below the sample stage. In order to avoid the collision, for example, when the magnetic field imaging lens 9 is moved downward along the optical axis O, the magnetic field of the magnetic field imaging lens 9 affects the photoelectrons from the sample 4. There is a risk that the state will change, making certain analyzes impossible. That is, by shifting the magnetic field type imaging lens 9 from a predetermined position, the photoelectron taking-in area by the field limiting diaphragm 16 and the analysis accuracy on the sample surface by the angle limiting diaphragm 17 are deviated from predetermined ones, and the sample 4 From which the photoelectrons are not focused on the aperture K1 of the field limiting diaphragm 16, and the photoelectrons are not sufficiently decelerated and are focused on the entrance slit S of the analyzer 14, resulting in difficulty in analyzing the desired sample. Become.

  The present invention has been made in view of the problems as described above. Even when the sample measurement is performed with the sample stage tilted, the present invention can be performed in a predetermined manner without interference between the sample stage and the magnetic imaging lens. It is an object of the present invention to provide a novel electron spectroscopic device which can be measured.

  An electron spectrometer according to the present invention comprises an irradiation means for irradiating a sample placed on a sample stage supported by a sample stage in an analysis chamber, a field-limiting diaphragm, a lens for decelerating and focusing electrons emitted from the sample, An electron spectrometer having an analyzer that sorts the decelerated and focused electrons by energy, and a detector that detects the electrons sorted by the analyzer, and is supported by a lens stage below the sample and is emitted from the sample An imaging lens for imaging the formed electrons on the field-limiting aperture, a sample stage drive mechanism capable of tilting the sample stage about an axis perpendicular to at least the optical axis, and at least the lens stage The lens stage drive mechanism that can be moved in the optical axis direction and the aperture diameter of the field limiting aperture can be changed. In an electron spectroscopic apparatus including a field limiting aperture opening diameter driving mechanism and a lens power source capable of changing the intensity of each lens, the sample stage driving mechanism, lens stage driving mechanism, field limiting aperture opening diameter driving mechanism, and lens A control device for controlling a power supply; a position where the imaging lens does not interfere with the sample stage with respect to an inclination angle of the sample stage; an aperture diameter of the field-limiting diaphragm with respect to the position of the imaging lens; and an intensity of each lens Storage means for storing the information, and the control device, when the sample stage is tilted, the position of the imaging lens according to the tilt angle from the storage means, and the position of the imaging lens The information on the aperture diameter of the field-limiting diaphragm and the intensity of each lens that can perform a predetermined analysis is called, and the lens is based on the called information. Stage drive mechanism, characterized in that form so as to control the opening diameter drive mechanism and lens power field stop limits.

  The electron spectroscopic apparatus of the present invention includes an irradiation means for irradiating a sample placed on a sample stage supported by a sample stage in an analysis chamber, a field limiting aperture, an angle limiting aperture, and decelerating and focusing electrons emitted from the sample. An electron spectroscope including a lens to be decelerated, an analyzer for selecting the decelerated and focused electrons by energy, and a detector for detecting the electrons selected by the analyzer, and supported by a lens stage below the sample. An imaging lens for imaging the electrons emitted from the sample on the field-limiting aperture, a sample stage drive mechanism capable of tilting the sample stage at least about an axis perpendicular to the optical axis, A lens stage drive mechanism capable of moving the lens stage at least in the optical axis direction, and changing the aperture diameter of the field limiting aperture An electronic device comprising: a field-limiting diaphragm aperture driving mechanism capable of changing the angle; an angle-limiting diaphragm aperture driving mechanism capable of changing the aperture diameter of the angle-limiting diaphragm; and a lens power source capable of changing the intensity of each lens. In the spectroscopic device, the sample stage driving mechanism, the lens stage driving mechanism, the field-limiting diaphragm aperture driving mechanism, the angle limiting diaphragm aperture driving mechanism, a control device for controlling the lens power supply, and the tilt angle of the sample stage Storage means for storing information on the position at which the imaging lens does not interfere with the sample stage, the aperture diameter of the field-limiting diaphragm with respect to the position of the imaging lens, the aperture diameter of the angle-limiting diaphragm, and the intensity of each lens The control device, when the sample stage is tilted, the position of the imaging lens according to the tilt angle from the storage means, and Information on the aperture diameter of the field-limiting diaphragm, the aperture diameter of the angle-limiting diaphragm, and the intensity of each lens that can perform a predetermined analysis with respect to the position of the imaging lens is called, and based on the called information, the lens A stage driving mechanism, a field-limiting diaphragm aperture driving mechanism, an angle-limiting diaphragm aperture driving mechanism, and a lens power source are controlled.

  According to the present invention, even when sample measurement is performed with the sample stage tilted, predetermined analysis and measurement can be performed very easily and without interference between the sample stage and the magnetic imaging lens.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 shows one schematic example of an electron spectrometer according to the present invention. In the figure, the same reference numerals as those used in FIG. 1 denote the same components.

  The photoelectron spectrometer shown in FIG. 2 differs from the photoelectron spectrometer shown in FIG. 1 in the following configuration.

  A sample stage control unit 31 for sending an electric signal for controlling the movement of the sample stage 5 in the X, Y, and Z directions or the inclination about the X or Y axis as a rotation center to the stage position adjusting mechanism 6, and the lens stage position adjusting mechanism 11, the lens stage control unit 32 for sending an electric signal for controlling the movement of the lens stage 10 in the X, Y, and Z directions, and the aperture diameter adjusting mechanism 18 of the field limit diaphragm 16. An angle limit for sending an electric signal for controlling the size of the aperture diameter of the angle limit stop 17 to the field limit stop control unit 33 for sending an electric signal for controlling the aperture and the aperture diameter adjusting mechanism 19 for the angle limit stop 17 An aperture control unit 34 is newly provided, and these units and the power supply unit 0 is form so as to operate in conjunction with a command from the control unit 21.

  In addition, a memory 35 for reading and reading data according to a command from the control device 21 is newly provided. In this memory, a magnetic field type connection in which the sample stage 5 and the magnetic field imaging lens 9 do not interfere with the inclination angle of the sample stage 5 is provided. Field of view limitation in which photoelectrons with high resolution and high sensitivity are detected by the detector 20 with respect to the position on the optical axis of the image lens 9 (position in the Z direction) and the position on the optical axis of the magnetic field type imaging lens 9 Data relating to the aperture diameter of the diaphragm 16, the aperture diameter of the angle limiting diaphragm 17, the applied voltage to the electrostatic lens 15, the supply current to the magnetic imaging lens 9, and the applied voltage to the analyzer 14 perform a predetermined analysis measurement. Is stored as an optimum condition.

  In the apparatus having such a configuration, when the sample 4 is to be analyzed while being tilted, when a command for tilting the sample 4 by a desired angle is given from the control device 21 to the sample stage control unit 31, the stage position adjusting mechanism 6 The sample stage 5 is tilted by a desired angle based on the tilt angle signal from the sample stage control unit 31.

  At this time, the control device 21 reads from the memory 35 the position on the optical axis of the magnetic field type imaging lens 9 corresponding to the tilt angle, the opening diameter of the field limiting diaphragm 16, the opening diameter of the angle limiting diaphragm 17, the electrostatic Optimal condition data relating to the applied voltage to the lens 15, the supply current to the magnetic imaging lens 9, and the applied voltage to the analyzer 14 are called, and a movement command based on the position data on the optical axis of the magnetic imaging lens 9 is called. To the lens stage control unit 32, an aperture diameter adjustment command based on the aperture diameter data of the field limiting aperture 16 to the field limiting aperture control unit 33, and an aperture diameter adjustment command based on the aperture diameter data of the angle limiting aperture 17 to the angle limited aperture control. The unit 34 is supplied with applied voltage data to the electrostatic lens 15, supply current data to the magnetic field type imaging lens 9, and applied power to the analyzer 14. Voltage application based on the data, and sends each interlocking current supply command to the power control unit 20.

  Then, in conjunction, the lens position adjusting mechanism 11 adjusts the position on the optical axis of the magnetic field type imaging lens 9 based on the position data from the lens stage control unit 31, and the aperture diameter adjusting mechanism 18 The aperture diameter of the field limiting aperture 16 is adjusted based on the aperture diameter data from the aperture control unit 33, and the aperture diameter adjusting mechanism 19 opens the angle limiting aperture 17 based on the aperture diameter data from the angle limiting aperture control unit 34. The aperture is adjusted, a voltage based on the applied voltage data from the power supply unit 20 is applied to the electrostatic lens 15, and a current based on the supply current data from the power supply unit 20 is supplied to the magnetic field type imaging lens 9. The applied voltage based on the applied voltage data from the power supply unit 20 is applied to the analyzer 14.

  As a result, the photoelectron spectrometer is in a state of so-called optimum measurement conditions in which the detector 20 can detect photoelectrons with high resolution and high sensitivity without interfering with the tilted sample stage 5 of the magnetic field imaging lens 9. Become.

  In this state, when the sample 4 is irradiated with X-rays from the X-ray source 7, photoelectrons are emitted from the sample, and the photoelectrons are focused on the field-limiting diaphragm 16 by the magnetic field type imaging lens 9. The photoelectrons that have passed through the aperture K1 of the field limiting aperture 16 and the aperture K2 of the angle limiting aperture 17 are decelerated by the electrostatic lens 15 and focused on the entrance slit S of the analyzer 14 and guided to the analyzer 14.

  The photoelectrons subjected to energy selection by the analyzer are detected by the detector 15, converted into an electrical signal, and output.

  The control device 21 generates a photoelectron spectrum based on the output signal and causes the display device 22 to display the photoelectron spectrum.

1 shows a schematic example of a conventional electron spectrometer. 1 shows a schematic example of an electron spectrometer of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Analysis chamber 2 ... Exhaust device 3 ... Sample holder 4 ... Sample 5 ... Sample stage 6 ... Sample stage position adjustment mechanism 7 ... Photoelectron excitation X-ray source 8 ... Power source of X-ray source 9 ... Magnetic field type imaging lens 10 ... Lens stage 11 ... Lens stage position adjusting mechanism 12 ... Electron spectrometer 13 ... Input lens 14 ... Analyzer 15 ... Detector 16 ... Field limiting aperture 17 ... Angle limiting aperture 18 ... Aperture diameter adjusting mechanism 19 ... Aperture diameter adjusting mechanism 20 ... Power supply Unit 21 ... Control device 22 ... Display device 31 ... Sample stage control unit 32 ... Lens stage control unit 33 ... Field-limited aperture control unit 34 ... Angle-limited aperture control unit 35 ... Memory S ... Incoming slit

Claims (3)

An irradiation means for irradiating a sample placed in a sample chamber supported by a sample stage with ionizing radiation, a field-limiting diaphragm, a lens for decelerating and focusing electrons emitted from the sample, and the decelerated and focused electrons as energy An electron spectrometer having an analyzer for sorting by the detector and a detector for detecting the electrons sorted by the analyzer; and the field-limiting aperture for the electrons emitted from the sample arranged and supported by a lens stage below the sample. An imaging lens for forming an image, a sample stage drive mechanism capable of tilting the sample stage at least about an axis perpendicular to the optical axis, and moving the lens stage at least in the optical axis direction Lens stage drive mechanism that can be used, and a field-limiting diaphragm aperture drive device that can change the aperture diameter of the field-limiting aperture And a lens power source capable of changing the intensity of each lens, wherein the sample stage driving mechanism, the lens stage driving mechanism, the field limiting aperture opening diameter driving mechanism, and a control device for controlling the lens power source are provided. , A position where the imaging lens does not interfere with the sample stage with respect to the inclination angle of the sample stage, information on the aperture diameter of the field limiting diaphragm and the intensity of each lens with respect to the position of the imaging lens is stored. And when the sample stage is tilted, the control device performs a predetermined analysis on the position of the imaging lens corresponding to the tilt angle from the storage means and the position of the imaging lens. Information on the aperture diameter of the field-limiting diaphragm that can be performed and information on the intensity of each lens can be called, and the lens stage driving mechanism, field control can be controlled based on the called information. Electron spectrometer which form so as to control the opening diameter drive mechanism and lens power supply aperture.   Irradiation means for irradiating the sample placed on the sample stage supported by the sample stage in the analysis chamber, a field limiting aperture, an angle limiting aperture, a lens for decelerating and focusing the electrons emitted from the sample, the decelerating and focusing An electron spectrometer equipped with an analyzer that sorts the collected electrons by energy, a detector that detects the electrons sorted by the analyzer, and an electron emitted from the sample that is supported by a lens stage below the sample. An imaging lens for forming an image on the field-limiting diaphragm, a sample stage driving mechanism capable of tilting the sample stage at least about an axis perpendicular to the optical axis, and the lens stage at least in the optical axis direction A lens stage drive mechanism that can be moved, and a field limit stop that can change the aperture diameter of the field limit stop. An electron spectroscopic apparatus comprising: an aperture diameter driving mechanism; an angle limiting aperture opening diameter driving mechanism capable of changing an aperture diameter of the angle limiting diaphragm; and a lens power source capable of changing the intensity of each lens. A stage driving mechanism, a lens stage driving mechanism, a field-limiting diaphragm aperture driving mechanism, an angle limiting diaphragm aperture driving mechanism, a control device for controlling the lens power supply, and the imaging lens with respect to the tilt angle of the sample stage. A storage means for storing information on a position that does not interfere with the stage, an aperture diameter of the field-limiting aperture for the position of the imaging lens, an aperture diameter of the angle-limiting aperture, and the intensity of each lens; When the sample stage is tilted, the apparatus corresponds to the position of the imaging lens corresponding to the tilt angle from the storage means and the position of the imaging lens. Information on the aperture diameter of the field-limiting diaphragm, the aperture diameter of the angle-limiting diaphragm, and the intensity of each lens that can be subjected to predetermined analysis, and based on the called information, the lens stage drive mechanism, the field-limiting aperture opening An electron spectroscopic device configured to control an aperture driving mechanism, an angle-limited aperture opening diameter driving mechanism, and a lens power source.   The electron spectrometer according to claim 1 or 2, wherein the ionizing radiation is X-rays.

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