JPH04233149A - Analyzing device for surface of sample - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample surface analysis apparatus capable of performing various types of analyzes in the depth direction of a sample surface.

0002

2. Description of the Related Art Generally, analysis in the depth direction from the surface of a sample uses a method in which surface analysis is performed while removing the surface of the sample by ion etching. Analyzers using this method basically combine an excitation radiation source that excites the sample, a device that detects secondary radiation emitted from the sample, and an ion gun that ion-etches the sample surface into a single vacuum. The structure is built into the container.

Conventional sample surface depth analysis devices are equipped with an X-ray source as a sample excitation source, and as a secondary radiation detection device, X-ray photoelectrons are selected as the secondary radiation to perform energy analysis. One type of excitation radiation source, such as an analysis device equipped with an energy analyzer that performs
It consisted of one type of secondary radiation detection device and an ion gun.

0004

[Problem to be Solved by the Invention] For example, while looking at the secondary electron image of the sample surface, X-ray spectroscopy is performed in the depth direction to qualitatively characterize the elements, and then X-ray photoelectron spectroscopy is used to determine the bonding state of the elements. If you want to investigate, you need an EPMA and an X-ray photoelectron analyzer, and at least one of them has to be equipped with an ion etching device. This poses an economical problem in terms of arranging the equipment, but it also avoids deterioration and contamination of the surface due to passing through the atmosphere during the transfer of the sample from one vacuum device to another. There was a problem of inefficiency as it was not clear and the analysis took a long time. The present invention aims to provide an analysis device that can perform various types of analyzes in parallel in the depth direction of a sample surface using a single device.

[0005]

[Means for solving the problem] An electron gun arranged so as to face a point on a sample, an electron optical system that focuses an electron beam formed by the electron gun on the sample surface, an X-ray source, and an ion gun. , an X-ray spectrometer, a charged particle energy analyzer, a mass spectrometer, and a secondary electron detector on the side of the sample.

[0006]

[Operation] According to the above-mentioned apparatus, the scanning electron microscope image of the sample surface can be displayed on the CRT by operating the electron gun, the electron optical system, the secondary electron detector, and the electron beam deflection means. can be visually observed, making it easy to select analysis points. Since there is an X-ray spectrometer that looks at the point irradiated by the electron beam, it is possible to perform elemental analysis using X-ray spectroscopy of the same area observed with the scanning electron microscope. Since the ion gun aims at the same location on the sample surface, ion etching can be performed at the same analysis point, allowing analysis to proceed in the depth direction. In addition, energy analysis and mass analysis can be performed on secondary ions emitted from a sample by ion irradiation with an ion gun, making it possible to analyze light elements that are difficult to analyze with X-ray spectroscopy. Since the same location is irradiated with X-rays, the energy analyzer described above can perform X-ray photoelectron analysis and determine the bonding state of elements in the sample. Each of these analyzes can be performed in the depth direction of the sample surface by operating the ion gun.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The figure shows an embodiment of the present invention. In FIG. 1, 1 is an electron gun, 2 is an electron lens that focuses the electron beam on the sample surface, 3 is a deflection coil that deflects the electron beam in the x and y directions on the sample surface, and S is the sample. Reference numeral 4 denotes a first ion gun whose ion beam is focused onto the sample surface by an ion lens system 5. Reference numeral 6 denotes a charged particle lens system that focuses charged particles emitted from the sample surface onto the entrance slit of the energy analyzer 7. The energy analyzer is of a cylindrical electrode type, and a charged particle lens system 8 and a quadrupole mass analyzer 9 are arranged coaxially on the output photometric axis of the energy analyzer 7, and a charged particle detector 10 is arranged behind it. is located. FIG. 2 shows the device in FIG. 1 rotated by 90% around a common optical axis N passing through an energy analyzer 7 and a mass analyzer 9, and each device 6, 7, and 8,
9 and 10 are shown in one block. 11 is an X-ray source, and 12 is a second ion gun for etching the sample surface. Further, 13 is a secondary electron detector placed on the side of the sample.

[0008] Various analytical methods using the above-mentioned apparatus and operations for performing the analysis will be described below. The electron gun 1, the electron lens 2, and the deflection coil 3 are activated, and the secondary electron detector 13 is activated.
When the output is displayed on the CRT 14, a scanning electron microscope image is obtained. 15 is a scanning signal generation circuit that sends scanning signals to the deflection coil 3 and CRT 14.

As above, when the electron gun 1 and electron lens 2 are operated, the lens systems 6 and 8 and the energy analyzer 7 are operated, and no voltage is applied to the mass spectrometer 9, the sample is irradiated with an electron beam. In addition to X-rays and secondary electrons, Auger electrons are also emitted from S, so energy analyzer 7
Electrons with a specific energy are selected through the lens system 8 and incident on the charged particle detector 10 as a substantially parallel beam bundle. Since the mass spectrometer 9 is a quadrupole type and no voltage is applied, the electrons travel straight and enter the detector 10. The detection output of the detector 10 is applied to the recorder 17 as a y-axis signal via the contact a side of the changeover switch 16. Energy scanning is performed by changing the voltage applied to the energy analyzer 7, and a signal corresponding to the applied voltage is sent to the recorder 17.
The energy spectrum of electrons emitted from the sample is recorded by applying it as an x-axis signal. From this record, the spectral peak of Auger electrons can be detected. Auger electron spectroscopy allows elemental analysis and chemical bond state analysis of extremely small regions of samples.

When the X-ray source 11 is operated instead of the electron optical systems 1 and 2 described above, X-ray photoelectrons are emitted from the sample surface. When these X-ray photoelectrons are analyzed and recorded in the same manner as in the case of Auger electron spectroscopy described above, an X-ray photoelectron spectrum is obtained, which allows average elemental analysis of the entire sample surface.

The ion gun 4 is operated, He is supplied as an ionized gas, the sample surface is irradiated with He ions, and the energy of the backscattered ions can be analyzed by the energy analyzer 7. In this case, the mass spectrometer 9 is not operated. The polarity of the voltage applied to the energy analyzer 7 is switched for positive ions. The changeover switch 16 is switched to the contact b side, and the output signal of the detector 10 is sent to the counter 18 for counting. The count of the counter for a certain period of time gives the intensity of scattered ions of a certain energy, and by performing energy scanning with the energy analyzer 7, the energy of the backscattered ions can be analyzed, and thereby the elemental analysis of the extreme surface of the sample can be performed. .

When Ar is supplied as an ionized gas to the ion gun 4 and the sample surface is irradiated with Ar ions, atoms on the sample surface are emitted as secondary ions. Energy analyzer 7
An appropriate voltage is applied to the lens systems 6 and 8 to operate the secondary ions to introduce the secondary ions into the quadrupole mass spectrometer 9. At this point, the mass spectrometer 9 is activated to perform mass scanning, and the detection signal of the detector 10 is passed through the b contact of the switch 16 and counted by the counter 18, in the same manner as in the case of scattered ions, to determine the constituent elements on the sample surface. Obtain the mass spectrum of In elemental analysis using this method, the Auger electrons and
It is possible to detect much smaller amounts of impurity elements than using line photoelectrons.

When the ion gun 12 is operated, the observation area on the sample surface can be ion-etched. Therefore, after performing some or all of the various analysis methods described above, etching the sample surface for a certain period of time, and then performing the various analyzes described above again.By repeating this operation, the analysis can proceed in the depth direction of the sample surface. I can go.

[0014]

According to the present invention, various analyzes in the depth direction can be performed while etching the sample surface while the sample is set in one device, and the sample can be transferred from one device to another. This eliminates the trouble of transferring the sample to another sample, significantly improving analysis efficiency, and since there is no transfer of the sample, there is no need for alignment when analyzing the same part of the sample, making it possible to conduct various analyzes of the exact same part. can. Furthermore, since the sample is not exposed to the atmosphere after being etched, no surface deterioration or contamination occurs.

[Brief explanation of the drawing]

FIG. 1 is a front view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the same as above.

[Explanation of symbols]

1...electron gun 4...First ion gun 7...Energy analyzer 9...Mass spectrometer 10...Charged particle detector 11...X-ray source 12...Second ion gun

Claims (1)

[Claims] As well as an electron gun and electron optical system arranged to point at a point on the sample surface, an ion gun for sample excitation, an ion gun for sample surface etching, an X-ray source, and an energy analyzer for the charged particle beam emitted from the sample. A sample surface analysis device comprising means for detecting secondary radiation from a sample, such as a mass spectrometer and a secondary electron detector.