JP4616631B2 - Sample analyzer - Google Patents

Description

  The present invention relates to a sample analyzer for the purpose of observing a minute region.

  There is a photoelectron spectrometer as an apparatus for analyzing the composition and chemical state of a sample. Such a photoelectron spectrometer irradiates finely focused electrons on the sample surface, and the photoelectrons generated from the sample ultrathin layer by the irradiation are focused by an incident lens and led to a cylindrical mirror analyzer or electrostatic hemispherical analyzer. To do energy spectroscopy. Then, the dispersed photoelectrons are detected by a detector, an energy spectrum of the detected photoelectrons is obtained, and the spectrum is analyzed to analyze the composition, chemical state, and the like of a micro region (nano-order level) of the sample. In other words, by calculating the amount of the predetermined element from the position of the peak appearing in the energy spectrum, the amount of the predetermined element on the sample surface can be determined, and measurement is performed by sequentially shifting the irradiation position of the electron beam, and the amount of element at each position is colored A photoelectron image can be obtained by mapping display corresponding to the above.

  Conventionally, in a photoelectron spectrometer using an X-ray or ultraviolet light source as an excitation source, an optical microscope with a position reading function has been used as means for specifying an analysis position when performing microanalysis. That is, the target position is searched with a position reading microscope capable of observing a wide range, and the position (coordinates) on the sample surface of this part is converted into the coordinate system of the sample stage mounted on the photoelectron spectrometer. The sample is introduced into the photoelectron spectrometer, and moved to the converted sample stage coordinates to analyze the target position. If necessary, photoelectron images around the target site are collected. If a peculiar part is found in the photoelectron image, this part is analyzed, and marking is performed at the position of the coordinate system of the photoelectron spectrometer.

  However, when the photoelectron spectrometer is used to analyze a position different from the part whose coordinates have been read with an optical microscope with a position reading function in advance, it is difficult to indicate where the analysis position is located on the optical microscope. This is because the amount of movement of the device from the reference point varies depending on the distortion of the image, the mechanical play of each device, and the like because a minute region is observed.

  In addition, as a prior art, there exists an electron microscope which carries out multiple exposure of the sample image, a figure, etc., and carries out expansion or reduction analysis (for example, patent document 1).

JP-A-5-258706

  The problem to be solved by the present invention is that it is difficult to indicate where the position analyzed by the photoelectron analyzer is located in the image obtained by the optical microscope with position reading function.

  The invention of claim 1 includes a sample holder on which a sample is placed and having a reference point of sample coordinates, and an XY table that holds the sample holder, reads the first image of the sample, and sets its coordinates. A position reading optical microscope, a sample stage for holding the sample holder, a primary beam source, and an energy analyzer for dispersing a secondary beam generated from the sample by the primary beam irradiated from the primary beam source. The first image is connected to a sample surface analyzer that reads the second image of the sample based on the output of the analyzer and sets coordinates thereof, the position reading optical microscope, and the sample surface analyzer. And storing and displaying the second image, and storing and storing information on the analysis target position designated based on the first image in association with the data of the first image. By controlling the sample stage holding the sample holder based on the information of the analysis target position, the analysis target position is arranged at the analysis position of the sample surface analyzer, and the second image of the sample is obtained. An information processing means for controlling the sample stage, wherein the information processing means is obtained from the sample surface analysis apparatus when a position different from the analysis target position for the sample is set as the additional analysis position. The additional analysis position information is coordinate-converted into position information of the position reading optical microscope, and the coordinate-converted information of the additional analysis position is stored in association with the data of the first image. It is a sample analyzer.

  The invention according to claim 2 is characterized in that the information processing means displays the additional analysis position on the first image based on the coordinate-transformed information of the additional analysis position. It is an analysis device.

  The invention according to claim 3 is the sample analyzer according to claim 1 or 2, wherein the primary beam is an electron beam and the secondary beam is an Auger electron beam.

The invention according to claim 4 is the sample analyzer according to claim 1 or 2, wherein the primary beam is an X-ray and the secondary beam is a photoelectron beam.

  According to the present invention, it is possible to record an analysis position by a newly added photoelectron spectrometer in an image obtained by an optical microscope. Thereby, it is possible to correlate the shape characteristic of the part analyzed from the image of the optical microscope and the analysis result by the photoelectron spectrometer. Here, the shape features include foreign matters, protrusions, discoloration, and the like.

  The configuration of the present invention will be described with reference to FIG. In FIG. 1, the analysis chamber 1 is kept airtight, and the inside is evacuated by a vacuum pump (not shown). The analysis chamber 1 is provided with a plurality of vacuum joints, and the devices are attached in an airtight manner. A sample stage 3 is attached to the analysis chamber 1. The sample stage 3 can be adjusted in the XYZ directions by an external sample stage position adjusting mechanism 4. A sample 2 placed on a sample holder 22 is placed on the sample stage 3.

  An X-ray tube 9 serving as a primary beam irradiation means is attached to the analysis chamber 1 so as to be inclined with respect to the surface of the sample 2.

  An incident lens unit 10 is attached to the center of the upper surface of the analysis chamber 1. The incident lens unit 10 condenses photoelectrons generated by being excited by the X-rays irradiated to the sample 2 from the X-ray tube 9. The incident lens unit 10 has an optical axis perpendicular to the surface of the sample 2. The incident lens unit 10 is composed of an electrostatic lens that collects and decelerates photoelectrons from the sample 2. At the end of the incident lens unit 10, an energy analyzer 11 that picks up the collected photoelectrons and extracts the photoelectrons having a specific energy, a detector 12 that detects the photoelectrons extracted by the energy analyzer 11, and the like are installed. ing.

  An optical microscope 6 with a zoom CCD camera is installed in the analysis chamber 1. An illumination device 8 is attached to the analysis chamber 1 and illuminates the observation position of the optical microscope 6.

  The energy analyzer control unit 14 controls the spectral energy of the energy analyzer 11 via the energy analyzer drive power supply unit 13, controls the lens conditions of the incident lens, receives the output of the detector 12, and extracts it with the energy analyzer 11. The counted photoelectrons are counted by energy.

  The monitor unit 15 receives the output of the CCD camera of the optical microscope 6 on which the optical image of the sample 2 is formed and controls the lens conditions of the optical microscope 6. The sample stage control device 5 controls the sample stage position adjusting mechanism 4.

  Further, the optical microscope 18 with a position reading mechanism is composed of an optical microscope 19 having a CCD camera 17 and an XY table 20, and includes the CCD camera 17 from directly above (in the normal direction) the placed sample holder 22. Measurement is performed with the optical microscope 19.

  The sample stage control device 5, the energy analyzer control unit 14, and the optical microscope 18 with a position reading mechanism are connected to a computer 16 having a monitor via an interface and are controlled by the computer.

FIG. 3 is a view of the sample 2 placed on the sample holder 22 and is observed with an optical microscope 18 with a position reading mechanism. FIG. 4 is observed with a photoelectron spectrometer. The observation point of the sample 2 is indicated by an offset (X ₁ , Y ₁ ) (X ₂ , Y ₂ ) (X ₃ , Y ₃ ) from the reference point 21 (X ₀ , Y ₀ ).

  The configuration of each unit in FIG. 1 has been described above. Next, the operation will be described.

First, the sample 2 placed on the sample holder 22 is observed with the optical microscope 18 with a position reading mechanism, which is a first measuring means for observing a wide area image, and two or more representative analysis target positions are determined. The coordinate value on the sample 2 of the determined analysis target position is read, and an optical microscope image as shown in the left of FIG. 5 including the analysis target position is electronically recorded. In FIG. 3, the coordinate values 23 (X ₁ , Y ₁ ), 24 (X ₂ , Y ₂ ), 25 (X ₃ , Y ₃ ) of the analysis target position are reference points 21 (X ₀ , Y ₀ ) of the sample holder 22. Offset value from. Of course, the reference point may be a part of the sample.

  Next, the sample 2 together with the sample holder 22 is introduced into a photoelectron analyzer which is a second measuring means for observing a narrow area image, and is mounted on the sample stage 3 in FIG. The position coordinates read by the optical microscope 18 with a position reading mechanism are affine transformed (coordinate transformation such as parallel movement and rotation) into the coordinate system of the sample stage 3 using the computer 16. The sample stage 3 is driven by the sample stage control device based on the converted coordinate position for the sample stage 3 to perform photoelectron analysis. At this time, a photoelectron image is also measured around the target site.

  In other words, X-rays narrowly focused on the surface of the sample 2 are irradiated from the X-ray tube, and the photoelectrons generated from the sample ultrathin layer by the irradiation are focused by the incident lens unit 10 and led to the electrostatic hemispherical energy analyzer 11. Spectral energy. Then, the dispersed photoelectrons are detected by the detector 12, the energy spectrum of the photoelectrons detected by the computer 16 is obtained, and the spectrum is analyzed to analyze the composition, chemical state, etc. of the micro region of the sample 2. That is, by calculating the amount of the predetermined element from the position of the peak appearing in the energy spectrum, the amount of the predetermined element on the surface of the sample 2 can be determined, and the measurement is performed by sequentially shifting the X-ray irradiation position. Is displayed in correspondence with the color, a photoelectron image as shown in the right of FIG. 5 can be obtained.

When a part requiring analysis is found in a part different from a preset analysis position from the obtained photoelectron image, a spectrum of this part is acquired and analysis measurement is performed. The coordinate position (X ₄ , Y ₄ ) on the sample stage 3 of the additional analysis position 26 in FIG. 4 newly added is recorded in the memory of the computer 16.

The coordinate position of the additional analysis position 26 recorded by the computer 16 is affine transformed into the coordinate system of the optical microscope 18 with a position reading mechanism. The coordinates of the additional analysis position 26 affine-transformed in the coordinates of the optical microscope image are converted into a vector value 27 for the recorded analysis target position 23 ′ (X ₁ , Y ₁ ). Based on the calculated vector value 27, the additional analysis position 26 is written in the analysis position data file associated with the optical microscope image recorded in the memory of the computer 16. The added analysis position is displayed on the monitor as shown in the left diagram of FIG.

  Although the operation has been described above, according to the present invention, the analysis position by the newly added photoelectron analyzer can be recorded in the image obtained by the optical microscope with a position reading mechanism. Thereby, it is possible to correlate the shape characteristic of the part analyzed from the image of the optical microscope and the analysis result by the photoelectron spectrometer. Here, the shape features include foreign matters, protrusions, discoloration, and the like.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, an Auger microprobe may be used as an electron gun instead of the X-ray source.

1 is an overview of an apparatus according to the present invention. It is an image figure which adds an observation position to an optical image from the photoelectron image by this invention. It is the coordinate diagram of the sample observed with the optical microscope. It is the coordinate diagram of the sample observed with the optical spectrometer. It is a measurement result in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Analysis chamber 2 Sample 3 Sample stage 4 Sample stage position adjustment mechanism 5 Sample stage control apparatus 6 Optical microscope 8 Illumination apparatus 9 X-ray tube 10 Incident lens unit 11 Energy analyzer 12 Detector 13 Energy analyzer drive power supply unit 14 Energy analyzer control unit DESCRIPTION OF SYMBOLS 15 Monitor 16 Computer 17 CCD camera 18 Optical microscope with position reading mechanism 19 Optical microscope 20 XY table 21 Reference point 22 Sample holder 23 Analysis target position 24 Analysis target position 25 Analysis target position 26 Additional analysis position 27 Vector value

Claims (4)

A sample holder on which a sample is placed and has a reference point of sample coordinates;
An XY table for holding the sample holder, a position reading optical microscope for reading the first image of the sample and setting its coordinates;
A sample stage for holding the sample holder, a primary beam source, and an energy analyzer for dispersing the secondary beam generated from the sample by the primary beam irradiated from the primary beam source, and the output of the analyzer A sample surface analysis device for reading a second image of the sample based on and setting coordinates thereof;
The position reading optical microscope and the sample surface analyzer are connected to store and display the first image and the second image, and the analysis target position designated based on the first image is displayed. Information is stored in association with the data of the first image, and the analysis target position is controlled by controlling the sample stage holding the sample holder based on the stored analysis target position information. An information processing means for controlling the sample stage so as to obtain a second image of the sample disposed at the analysis position;
In a sample analyzer equipped with
The information processing means further coordinates the information of the additional analysis position obtained from the sample surface analysis device into the position information of the position reading optical microscope when a position different from the analysis target position is set as the additional analysis position for the sample. The sample analysis apparatus characterized in that the converted and coordinate-converted information on the additional analysis position is stored in association with the data of the first image . 2. The sample analyzer according to claim 1, wherein the information processing unit displays the additional analysis position on the first image based on the coordinate-transformed information on the additional analysis position . The sample analyzer according to claim 1 or 2 , wherein the primary beam is an electron beam, and the secondary beam is an Auger electron beam. 3. The sample analyzer according to claim 1 , wherein the primary beam is an X-ray and the secondary beam is a photoelectron beam.

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