JPH0119804Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an etching device for a sample surface in an X-ray microanalyzer or an Auger electron analyzer.

In an X-ray microanalyzer, a narrowly focused electron beam is irradiated onto a sample, the characteristic X-rays generated at that time are separated into spectra using a spectroscopic crystal, and qualitative and quantitative analyzes of the sample are performed based on the detected signals. In this case, it is not enough to simply analyze the surface of the sample.
Depth analysis is often required. When performing this depth direction analysis, conventionally, mechanical polishing means is used to perform diagonal polishing at an angle of several degrees so that the faults in the depth direction appear, and then the electron beams are generated along the faults created by the polishing. The irradiation point of the line is moved.

However, since this method uses mechanical polishing, the polishing work is very troublesome, and
Since it is almost impossible to perform polishing in the sample chamber of a line microanalyzer, polishing cannot be performed during the analysis, and furthermore, the polishing angle cannot be minutely controlled. Unable to obtain resolution.

On the other hand, in the Auger electron analyzer, since the layer that generates Auger electrons is limited to the very surface layer of the sample, it is necessary to remove dirt from the sample surface and perform analysis with a fresh sample exposed. For this reason,
Conventionally, an ion gun is attached to a sample chamber, and a method has been adopted in which an ion shower is applied to the sample surface before analysis, and the surface layer of the sample is etched by the ions. When performing depth analysis while sequentially peeling off the surface atomic layers by etching with an ion shower, there is still a limit to the depth resolution, and since the analysis is performed while removing the surface layer, it is difficult to reproduce the analysis. There are disadvantages such as lack of accuracy and inability to perform line analysis in the depth direction.

Therefore, the purpose of the present invention is to focus on the above points and to propose a sample surface etching device that can perform diagonal polishing at minute angles and perform depth direction analysis with ultra-high resolution. .

The configuration of the present invention is such that an ion beam is directed toward the sample surface in an apparatus equipped with a means for irradiating a sample surface with radiation or a charged particle beam, and a means for detecting X-rays and electrons generated from the sample as information by the irradiation. An ion source for irradiating the ion beam, an X and Y deflector for scanning the ion beam on the sample surface, and a scanning signal that transmits a signal that changes quadratically to one or both of the X and Y deflectors. The present invention is characterized by a sample surface etching device used in an analytical device, etc., which has a power source supplied as a power source.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a case where the present invention is applied to an Augier electron analyzer, and 1 is a test sample. An electron column 2 is provided facing the sample, and is capable of irradiating the sample surface with an electron probe. The electron column is
It usually has an electron gun, a focusing lens, a deflection system, an objective lens, etc. Reference numeral 3 denotes an Augier electron spectrometer, which uses, for example, a cylindrical mirror type analyzer, and sorts and detects Auger electrons generated from the sample 1 by irradiation with an electron probe from the electron column 2 according to their energy. Although not shown, the detection signal from the spectrometer is sent to a display device and recorder through a signal processing circuit to obtain an Augier spectrum. 4 is an ion gun, and the ion beam IB fired from this is passed through X and Y deflectors 5X,
5Y onto sample 1. This deflector 5X is connected to an X-direction scanning signal generator 9X via an amplifier 6X, a quadratic curve generator 7, and a changeover switch 8, and is supplied with an X-direction scanning signal (voltage). Further, the deflector 5Y is connected to a Y-direction scanning signal generator 9Y via an amplifier 6Y, and is supplied with a Y-direction scanning signal. Both scanning signal generators generate sawtooth wave signals, and the period of 9Y is selected to be several tens to hundreds of times larger than that of 9X. When the changeover switch 8 is connected to the a terminal, the sawtooth wave signal as shown in FIG. 2a from the horizontal scanning signal generator 9X is 2.
When passing through the next curve generator 7, 2 as shown in FIG.
It is converted to the following curve or a curve approximating it. When this signal is applied to the deflector 5X via the amplifier 6X, the X direction scanning is slow at the initial point,
It gradually becomes faster. As a result, the ion irradiation amount by scanning in the X direction becomes as shown in FIG. 3, and is higher in the area where the voltage change is smaller in FIG. 2b. Therefore, the etching is as shown in FIG. 4, and an oblique polished surface 1a is obtained. The angle of this polishing surface 1a can be arbitrarily adjusted by changing the coefficients of the quadratic curve generator 7 shown in FIG.

Now, suppose that the ion beam is scanned so that it moves 1 mm in the X direction and creates a depth difference of 1000 Å. At this time, when performing Auger electron analysis by scanning in the X direction using an electron probe with a diameter of 1000 Å, the movement of the 1000 Å electron probe is in the depth direction.
The movement is 0.1 Å, and even if it is moved 1 μm in the X direction, the depth is 1 Å, indicating that it has high resolution in the depth direction.

After completing this diagonal polishing, the electron column 2
By irradiating the polishing surface 1a with an electron probe and analyzing the energy of the Auger electrons generated therewith using the spectrometer 3, qualitative and quantitative analysis of the irradiation point is possible. Furthermore, by moving the irradiation position of the electron probe in the X direction of the polished surface 1a while detecting Auger electrons with only a specific energy, an oblique tomographic Augier line profile can be obtained, which makes it possible to know the analysis of specific elements. can. At this time, the electron probe is scanned two-dimensionally on the polishing surface 1a,
By introducing the detection output of Auger electrons into a cathode ray tube that is synchronized with its scanning, it is possible to display images with depth direction information based on specific elements.

The above example shows the case where the X-direction scanning signal is quadratic modulated, but it is also possible to modulate only the Y-direction scanning signal or both the X-direction and Y-direction scanning signals simultaneously.
It may also be modulated in the following curve. Also, although the explanation was given regarding the Augier electron analyzer,
It goes without saying that the present invention can be similarly applied to other analytical devices such as a line microanalyzer.

As detailed above, the present invention scans the ion beam along a quadratic curve or a curve approximating it, thereby continuously changing the ion beam irradiation amount in the scanning direction. This makes it possible to perform diagonal polishing with ultra-small angles, and it is possible to obtain high resolution in the depth direction by analyzing along the polished surface.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the scanning signal waveform in the apparatus shown in FIG. 1, FIG. 3 is a diagram showing the ion beam irradiation dose distribution on the sample surface, and FIG. FIG. 4 is a partial cross-sectional view of the sample showing the polished state. 1: sample, 1a: polished surface, 2: electron column,
3: Augier electron spectrometer, 4: ion gun, 5X:
X deflector, 5Y: Y deflector, 6X, 6Y: amplifier, 7: quadratic curve generator, 8: selector switch, 9
X: X direction scanning signal generator, 9Y: Y direction scanning signal generator.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an apparatus equipped with a means for irradiating a sample surface with radiation or a charged particle beam and a means for detecting as information X-rays and electrons generated from the sample by the irradiation, An ion source for irradiating an ion beam toward the target, an X and Y deflector for scanning the ion beam on the sample surface, and one or both of the X and Y deflectors that change in a quadratic curve. A sample surface etching device for an analytical device, etc., which has a power supply that supplies signals as scanning signals. 2. A sample surface etching device in an analytical device or the like as claimed in claim 1, wherein the power source is configured to output a sawtooth wave signal and a signal changing in a quadratic curve.