JPH01500547A - Apparatus and method for local chemical analysis on the surface of solid materials by X-photoelectron spectroscopy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Device and method for local chemical analysis on the surface of a solid material using X-photoelectron spectroscopy law The present invention provides an apparatus for local chemical analysis on the surface of solid materials by X-photoelectron spectroscopy. and its method.

X photoelectron spectroscopy, called (XPS), uses X photons placed in an ultra-vacuum chamber. It consists of irradiating a sample and analyzing the energy of the photoelectrons it emits.

The energy spectrum of photoelectrons is related to the chemical composition of the surface and the nature of chemical bonds. information. The various X-photon sources used may be: You could think so: tat consists mainly of an anticathode bombarded by an electron beam (XvA tube), Same type as used in line photography or XvA crystallography.

Synchrotron radiation provided by a particle accelerator of the type consisting of (bl).

(J, C of REIMS University, where the C1 sample or sample support serves as an anticathode) The one recommended by the AZAUX method, in which one of the surfaces is electrically When bombarded by the child beam and the sample and its support are sufficiently thin , photoelectrons are generated on opposite surfaces.

Using an X-photon source as described above, the surface area typically analyzed is 1012. Rumo The use of known techniques as described above to reduce the surface area analyzed It consists of the following:

1”) Standardize the X source. Less zones will be illuminated, but the flow of X photons will increase. The flux decreases by the same amount as the detected signal signal/noise reduction λb/1%Azdami- 2@) A device placed at the entrance of the analyzer, or an analyzer with a small field of view due to its design. In reducing the surface area analyzed, this system has the same drawbacks as the previously mentioned one. do.

3@) Focusing X-rays by one grating (reso).

However, this result is obtained at the cost of a large loss in signal/noise ratio, This requires the use of multi-collection detectors.

4°) Generation of X photons in a thin anticathode by a focused electron beam. Na The thin sample is integrated with this anticathode.

(Methods J, CA, ZAUX).

The method of J. CAZAUX currently has the best resolution, that is, a few micrometers. However, since this method is only applicable to thin samples, Its scope of use is severely limited.

Results on thin samples of approximately 0.1-1 micron using the method of J.CAZAtJX. However, as experts in the field know, it is difficult to obtain There are major problems with samples of this size; on the other hand, surface analysis techniques This is extremely difficult to control for sample surfaces such as Sometimes it can be as many as several atomic JIL layers. Furthermore, cleaning the sample is important. This naturally brings out a number of problems.

If the X-rays are collected by a grid, the cost of the X-ray source and monochromator is 100 More than 10,000 francs.

The cost of a conventional X-ray source with feed is approximately 300,000 to 500,000 francs.

On the one hand, the present invention is not limited by the dimensions of the sample and allows any size, and on the other hand, On the other hand, it can vary from about 100 microns to 1 mm at extremely low cost. X-photoelectron spectroscopy allows analysis of surfaces with diameters of This invention relates to an apparatus and method for local chemical analysis on the surface of body materials. Ru.

According to the device according to the invention, the surface to be analyzed is scanned using a scanning electron microscope. While localized on the surface, localized on the surface of the block material by X photoelectron analysis. chemical analysis can be realized.

Thus, more precisely, the object of the invention is to combine an electron beam with a block solid material. Collision is placed as close as possible to the block sample between the sample blocks. X-photon microsource consisting of a combination of a meter and a body 7 confining an anticathode , the relationship between such elements is detected after reflection on the sample. The main body must be such that it blocks the incident electrons of the electron beam, so that The anticathode is thick enough to stop most of the electrons in the electron beam, but only a few of the X photons produced. be thin enough to limit absorption, and the collimator should be thin enough to limit absorption, and the collimator should be Anticathode in relation to the internal cylinder of the analyzer as well as the collimator masking the emission surface of the sample, thus directing the photoelectrons emitted by the sample to the analyzer. [al] Connected to a manipulator located externally. an ultra-vacuum analysis chamber (b) in which a sample to be analyzed is stored; l Analyzer located near the sample fc) Electrons that emit an electron beam an apparatus for local chemical analysis of solid material surfaces by X-photoelectron spectroscopy, including a source.

It is also an object of the invention to provide a An X-photon microsource consisting of a body confining a collimator and an anticathode is The relationship between such elements consists of intervening The main body blocks the incident electrons of the electron beam so that they are not detected. That is, the anticathode was created thick enough to stop most of the electrons in the electron beam. be thin enough to limit the absorption of X photons, and the collimator This reduces the emission angle of the sample in relation to the internal cylinder of the analyzer and collimator. masking the emission surface of the anticathode, and thus the photoelectrons emitted by the sample are separated. It is characterized by being guided to an analyzer, fa+　Solid to be analyzed connected to a manipulator in an ultra-vacuum analysis chamber Insert the sample, (C)'gj, the electron beam emitted from the source. Local analysis is performed on the surface of solid materials using X photoelectron spectroscopy, which scans the sample with Here's how to do it.

Similarly, the invention considers the following features individually or in combinations thereof that are technically possible: It is also related to consideration of the combination of the X photon microsource itself. contains three graduated cylinders, the first of which is at the diameter of the electron beam. big compared to

- the anticathode is integral with the smallest diameter cylinder of the body of the X-photon microsource and is thin; be constructed of a thin metal film.

- The thickness of the thin metal film is between 1 micron and 50 microns.

- metal films, aluminum, magnesium, chromium, copper and similar materials; Must be selected from the group of metals that include.

- The diameter of the sample surface to be analyzed is approximately 100 microns.

- The sample is tilted according to an angle of approximately 45 degrees.

- The thickness of the partition wall of the main body of the X-photon microsource is greater than 20 microns.

- X-photon microsource body to which the collimator is fixed by welding; It is an element that extends the.

- The collimator covers the X-photon microsource body, which is fixed to it by an inset. Being an element that extends.

- The X-photon microsource is moved outside the ultra-vacuum analysis chamber by a manipulator. be controlled by.

-Equipment for electron beam focusing and scanning, secondary electron detector, microsource and sample Contains the electronic elements necessary to obtain an electronic image of the surface.

Various advantages and features of the present invention can be seen by contrast with the accompanying drawings, including: You can understand from the detailed explanation given below: FIG. 1 is a schematic diagram (flow chart) of the present invention.

FIG. 1A shows a particular implementation B of the invention.

FIG. 2 is a schematic diagram of an apparatus according to the invention.

FIG. 3 is a detailed diagram of the X-photon microsource.

FIG. 4 shows a first embodiment of an X-photon microsource according to the invention. .

FIG. 5 shows a second embodiment of an X-photon microsource according to the invention. .

FIG. 6 is a sectional view taken along the line ■-■ in FIG. 7.

FIG. 7 is a sectional view taken along the line Vl-Vl of the 6th R.

Figures 8V and 9 show the experimental results, where the abscissa represents the electric volt unit. The energy of the photoelectron is expressed in degrees, and the number of impacts per second is plotted on the ordinate. .

In the accompanying drawings in which like reference numbers indicate like parts, X-photoelectron spectroscopy The device for local chemical analysis on the surface of solid materials by (Figure 2).

The device 22 is arranged in a known manner external to the electron source 5 emitting the electron beam 10. The superstructure containing the sample to be analyzed is connected to the manipulator 3. It includes a vacuum analysis chamber 1 and an analyzer 4. X photon micro saw The beam 6 is interposed between the electron beam 10 and the sample 2, as close to the sample 2 as possible. It is being

The X-photon microsource according to the invention consists of three elements: a body 7, a thin It consists of a metal film or anticathode 8 and a collimator 9.

The main body 7 of the X-photon microsource 6 contains the incident electrons and the electrons re-emitted by the anticathode 8. Three staged cylinders 13.14.15 are included to capture the offspring. No. The diameter of the cylinder 13 in No. 1 is large enough to catch interfering electrons accompanying the electron beam 10. These electrons are large compared to the diameter of the electron beam 10 due to This is due to the interaction of the electron beam with the diaphragm of the electron source 5 or the electron mirror. child Due to the general shape obtained from these graduated cylinders 13.14.15 approximately 45 degrees The surface of the sample 2 tilted at an angle of can be brought closest to the surface of the sample 2.

The X-photons are created in the metal film or antagonist piis. The materials used are , -i used to make the anticathode, i.e. aluminum, magnesium. metals such as aluminum, chromium, copper, and similar metals. The thickness of metal film 8 is , must be such that all incident electrons must be stopped. , as small as possible to minimize the absorption of X photons before they exit from the anticathode 8. It has to be something special. For example, for a 15KV electron beam 10, the thickness A thin aluminum film with a diameter of 3 microns is good. The method is variable between 1 and 50 microns. The structure of the anticathode 8 of the present invention is, on the one hand, ensure sufficient photon flux and, on the other hand, ensure that the emission surface or end faces directly to the analyzer. Make sure they don't clash. In other words, the anticathode 8 is located as close as possible to the sample 2 and the analysis This is positioned so that the surface to be analyzed for instrument 4 is not masked. It is important to be there. In other words, the closer the anticathode 8 is to the sample 2, the more it will be analyzed. The surface to be covered becomes smaller.

The collimator 9 is the third component of the X-optoelectronic microsource 6 of the device according to the invention. component. The primary purpose of collimator 9 is to improve the analytical spatial resolution. The purpose is to reduce the irradiated surface of the sample 2. The electron beam 10 is inside the anticathode 8. The irradiated surface 19 of sample 2 is focused on the center (point 0 in Figures 6 and 7). is obtained by drawing a straight line starting from the zero point and passing through the lower end of the collimator 9. It is delimited by the closure curve A, FBEA (Fig. 7). [Electron beam lO is strictly In the real case, which is not localized to a dense point, the irradiated surface 19 is The expansion due to this effect is equivalent to a 10% increase in the irradiated surface. There is a possibility that it is small.

At the end of the collimator 9, on the one hand, the collimator 9 analyzes the irradiated surface 19 of the sample 2. On the other hand, in order to avoid masking in relation to the container 4, and on the other hand, in the collimation 9. The side cylinder and anticathode 8 are designed not to face the analyzer 4. Conclusion station, these elements emit photoelectrons 12 because they are irradiated with X photons, As a result, if these are detected by the analyzer 4, a disturbance signal will be emitted.

The collimator 9 therefore consists of two inclined planes (p, and P2). The positions of these planes are determined as follows. When the electron beam 10 is vertical, the axis of the analyzer 4 is horizontal, and the sample 2 is tilted at 45 degrees. Let us consider the case (Fig. 6), where the radius R of the collimator 9 is determined by mechanical manufacturing considerations. The angle is selected based on considerations, and the angle is determined by considering the intensity of the X photon beam 11. be done. Two parameters R and α determine the location of point C. horizontal through 0 point A plane P2 is derived that is inclined at an angle of 1 θ/2 with respect to the line. Note that θ/2 is the value of analyzer 4. It is half of the acceptance angle. The intersection of this plane and the cylinder 2R is point D. point D Create a plane that forms an angle of θ/2 with the horizontal line. Intersection of this plane and straight line OC The point is point A. Since point A is one point in sample 2, in this way The position of the sample to be engraved on the base 6 is determined. Based on the configuration described above, the following The following size can be derived: tgα 3) Anticathode 8-Sample 2 4) Dimensions of irradiated surface 19 of sample 2 Therefore, following the geometry shown in Figures 6 and 7, the R-25 micron , α=25″′, θ/2=30°, the following values can be found: OH,= Micron, OH! =82 microns, 0H4=200 microns, AB=200 microns Ron and EF = 150 microns.

In the X-photon microsource 6 according to the invention, the collimator 9 is an element extending the body 7 fixed to it by any means. For example, the collimator 9 is welded to the body 7 as shown as 16. or fixed by inset as shown at 17 (Fig. 4 and and Fig. 5), the purpose of the X-photon microsource 6 is to be detected after reflection on sample I42. The goal is to block incoming electrons. The bulkhead of the main body 7 has sufficient thickness. 20 mm to stop the photons emitted in the direction of the wall of the main body 7. It exhibits a greater thickness than Chron.

The X-photon microsource 6 is controlled by a manipulator 18. Manipure The motor 18 can move the anticathode 8 within the ultra-vacuum chamber 1. Mani The coupling between the generator 18 and the anticathode 8 enables electrical isolation of the anticathode 6. Information is given about the intensity of the electron beam 1° and thus the intensity of the X photons. Conventional In this technology, X-ray B has already been placed in an ultravacuum, In some cases, the cathode is large and must be located very far from the sample. There wasn't. Since the source is very far from the sample, -i has about 150 W, T requires very high power, which means that cooling of the anticathode by the fluid is necessary. It implies rejection. As a result, the irradiated surface of the sample is approximately 10f12, and the local analysis cannot be obtained.

One of the features of the present invention is that there is no limit to the size of the sample, and it can exhibit any size. The point is that it can be done. - Localized area obtained by the device and method based on the strength tree invention Analyzes cannot currently be obtained with equipment using conventional techniques when using solid block samples. This ensures an analysis range for samples within the 100 micron range, which is impossible to achieve with a 100 micron range.

This analysis range requires an x-ray focusing system in devices based on prior art technology.

8 and 9, the energy window width of the analyzer is 3 eV, and the intensity is 0. Spectra obtained for silver and copper samples with a beam of 7 μA 1 energy 40 KeV It shows the vector. Acquisition time for copper spectrum is 3 hours, securing silver spectrum The time is 1/2 hour.

The coefficient rate corresponding to the highest peak of the copper spectrum is 7000 counts/sec.

This result shows that this modulus velocity is The device and method according to the invention is found to be 10 times greater than that obtained by On a surface of 100 microns in diameter using an X-ray source based on conventional technology The same modulus velocity is obtained as that obtained on the surface of a 10-diameter irises.

Accordingly, those skilled in the art will recognize the following important benefits that may be obtained by implementing the present invention. Inexpensive equipment that will make you understand the point - Possibility to use samples whose dimensions are not restricted.

- Possibility to obtain analyzed surfaces of approximately 100 microns in diameter.

- Possibility to localize the analysis by scanning electron microscopy.

The invention is not limited to the embodiments shown and detailed herein; Various modifications can be made without departing from its scope.

Engraving (no changes to the content) Procedural amendment (formality) %formula% 3. Person who makes corrections Relationship to the case: Applicant Name: Anstlemann Societe Anonymous 5, date of amendment order: 1986 November 22nd 6, Target of amendment Translation of drawings (Figures 8 and 9) 7, Of the amendments Contents: As shown in the attached sheet Engraving of the Banwa translation of Figures 8 and 9 (no changes in content) International search report ANNEX ToτHE INTERNATION Ar, FEA, RCHREP ORT ON

Claims (1)

[Claims] 1. The block is placed between the electron beam (10) and the sample (2) which is a block solid material. The collimator (9) and anticathode ( X-photon microsource (6) consisting of a combination of a body (7) confining an The relationship between such elements (7, 8, 9) is determined by the reaction on the sample. The main body (7) blocks the incident electrons of the electron beam (10) so that they are not detected after the injection. The anticathode (8) should be of a type that absorbs most of the electron beam (10). thick enough to stop the photons, but sufficient to limit absorption of the generated X photons (11) be thin and the collimator (9) reduces the emission angle of the photons (11). In relation to the inner cylinder of the analyzer (4) and the collimator (9) Masking the emission surface of the anticathode (8) and thus the light emitted by the sample (2) characterized in that the electrons (12) are guided into the analyzer (4) (a) outside thereof; The sample to be analyzed (2) connected to the manipulator (3) placed in Ultra-vacuum analysis chamber (1) housed in (b) Analyzer (4) positioned near the sample (c) Electron beam (10) Local chemistry of solid material surfaces by X-photoelectron spectroscopy, including an electron source (5) that emits Analysis equipment. 2. Said, the body (7) of the X-photon microsource (6) consists of three graduated cylinders ( 13, 14, 15), of which the diameter of the first cylinder (13) is the electron beam. (10) The device according to claim 1 is characterized in that the device is larger than the diameter of the device. Place. 3. The anticathode (8) has the minimum diameter of the main body (7) of the X-photon microsource (6). It is integrated with the cylinder (15) and is made of a thin metal film (membrane). An apparatus according to claim 1 or 2, characterized in that: 4. The thickness of the thin metal film (8) is between 1 micron and 50 microns. The device according to any one of claims 1 to 3, characterized in that: Place. 5. The metal film (8) is made of aluminum, magnesium, chromium and copper. of the grooves comprising: The device according to any one of Items 1 to 6. 6. The diameter (19) of the surface to be analyzed of the sample (2) is about 100 microns. The device according to any one of claims 1 to 5, characterized in that: . 7. characterized in that the sample (2) is inclined according to an angle of about 45°; An apparatus according to any one of claims 1 to 6. 8. The thickness of the partition wall of the main body (7) of the X-photon microsource (6) is 20 microns. any one of claims 1 to 7, characterized in that the The device described in. 9. said X-ray, to which the collimator (9) is fixed by welding (16); It is an element that extends the main body (7) of the child microsource (6). A device according to any one of claims 1 to 8, characterized in that: 10. said collimator (9) is fixed thereto by an inset (17) being one element extending the body (7) of the photon microsource (6) An apparatus according to any one of claims 1 to 8, characterized in that: 11. The X-photon microsource (6) is superimposed by the manipulator (18). The vacuum (1) is controlled externally to the analytical chamber (1). The device according to any one of items 1 to 10. 12. The device (23) for converging and scanning the electron beam (10), the secondary electron detection Necessary for obtaining electron images of the surface of the sample (2), microns (21) and Claims 1 to 3 are exempted from including the necessary electronic elements. The device according to any one of items 11 to 11. 13. between the electron beam (10) and the sample (2) and as close as possible to the sample (2). from the body (7) that confines the collimator (9) and anticathode (8). intervening an X-photon microsource (6) consisting of such an element The relationship between the components (7, 8, 9) is such that the voltage is not detected after reflection on the sample (2). The main body (7) should be such that it blocks the incident electrons of the child beam (10). , the anticathode (8) is thick enough to stop most of the electrons in the electron beam (10), but be thin enough to limit the absorption of X photons (11) produced; and The collimator (9) reduces the emission angle of the photons (11) and the analyzer (4) as well as Massaging the emission surface of the anticathode (8) in relation to the internal cylinder of the collimator (9) The photoelectrons (12) thus emitted by the sample (2) are sent to the analyzer (4). It is characterized by being led to (a) The sample to be analyzed connected to the manipulator in the ultra-vacuum analysis chamber (1) inserting a solid sample (2); (b) placing an analyzer (4) near such sample (2); (c) Scanning the sample (2) with the electron beam (10) emitted from the electron source (5) , A method of performing local analysis on the surface of a solid sample using X-photoelectron spectroscopy.