JPH0325358A - Scanning type x-ray analysis apparatus for very small part - Google Patents

Abstract

PURPOSE:To efficiently execute the element analysis of the foreign matter contained in a sample and the observation of its shape, etc., down to the deep part of the sample by ion milling the sample surface irradiated with an electron beam. CONSTITUTION:The irradiated part of the sample 1 is ion milled and a very small recess 1a is formed on the surface of the sample when the very small part of the sample 1 is irradiated with the ion beam 10 focused by an ion milling device 9. An X-ray 4 of a specific wavelength and the secondary electron 6 specified by the shape are respectively radiated from the element contained in the very small foreign matter 11 existing in the bottom of the recess 1a when the ion-milled recess 1a of the sample 1 is irradiated with the finely focused electron beam 2 while the beam is scanned. The X-ray 4 of the specific wavelength and the secondary electron 6 are detected by the method similar to the conventional method and the detection signal thereof is processed by which the element analysis of the material contained in the foreign matter and the shape observation of the foreign matter are simultaneously executed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a scanning type microscopic X-ray analysis device.

[Conventional technology]

A micro-section X-ray analyzer irradiates a finely focused electron beam onto a microscopic section of a solid sample to be analyzed, and performs elemental analysis of the irradiated sample section using the X-ray spectrum emitted from the irradiated section of the sample. It is a device that performs semiconductor devices,
It is widely used for elemental analysis contained in electronic components such as solid-state imaging devices and other thin film stacked devices.

As shown in Fig. 3, the scanning type microscopic X-ray analyzer includes an electron gun 3 that emits a narrowly focused electron beam 2 that scans and irradiates a sample l placed in the air, and a An X-ray detector 5 having an X-ray spectrometer that selectively detects X-rays 4 of a specific wavelength emitted from a minute part of the sample 1 by irradiation with the electron beam 2; The secondary electron detector 7 detects the secondary electrons 6 emitted from the part.

Using the above-mentioned apparatus, the electron beam 2 irradiated onto the sample 1 is scanned, and X-rays 4 of a specific wavelength emitted from a specific element emitted from a minute part of the sample 1 are transmitted. On the other hand, by scanning the image beam of this cathode ray tube oscilloscope 8 in synchronization with the sample scanning electron beam 2, the concentration distribution of a specific element in a minute part of the sample corresponding to the detected X-rays of a specific wavelength can be detected on the cathode ray tube. It can be displayed on a screen (Japanese Utility Model Publication No. 45-27672).

In addition, the sample 1 is
A secondary electron detector 7 detects the secondary electrons 6 emitted from the microscopic part of the sample, and the shape of the unevenness of the irradiated microscopic part is observed based on this detection signal, and it is determined that the shape corresponds to the concentration of the specific element in the microscopic part of the sample. It is possible to consider the contained elements.

[Problem U that the invention attempts to solve]

The above-mentioned scanning type microscopic X-ray analyzer can perform elemental analysis of foreign substances contained in microscopic parts of semiconductor devices, solid-state imaging devices, and other thin-film multilayer devices, and observation of the shape of microscopic parts with high precision and efficiency. is possible.

However, elemental analysis of foreign substances contained in minute parts of the sample 1 can be performed using the X-rays 4 of the specific wavelength emitted from the sample 1 by irradiating the electron beam 2 with the sample 1.
The secondary electrons 6 are limited to a depth of about 2}j-m from the surface of the sample 1, and are emitted from the sample 1 to observe the shape of the unevenness of the laminated thin films in the microscopic regions of the sample 1. This is possible only at a depth of about 0.1 pm from the surface of the sample I. For this reason, it is difficult to analyze foreign substances contained in deeper parts of the sample 1 and observe their shapes, and it is difficult to analyze the foreign substances contained in the deeper parts of the sample 1 and observe their shapes. In some cases, the purpose may not be fully achieved.

In view of the above-mentioned conventional problems, it is an object of the present invention to perform elemental analysis of foreign substances contained in samples such as semiconductor devices, solid-state image sensors, and other thin film stacked devices, and to observe their shapes in a way that is easier than before. The object of the present invention is to provide a scanning type microscopic X-ray analysis device that can efficiently perform even the smallest part.

[Means to solve the problem]

The above purpose is to provide a means to scan and irradiate the surface of a sample to be analyzed with a narrowly focused electron beam, and to select an X-ray of a certain wavelength from among the X-rays emitted from the sample surface by irradiation with this electron beam. In the scanning type microscopic X-ray analysis apparatus, the scanning microscopic X-ray analysis apparatus has a means for detecting the microscopic part of the sample, and a means for observing the shape of the microscopic part of the sample from the secondary electrons emitted from the sample surface by irradiation with the electron beam. This is achieved by providing an ion milling device that mills the sample surface that is irradiated with an electron beam.

[Effect]

The above method uses an ion milling device to perform ion milling (shaving off the υ surface by ion collision) on the part of the sample surface that is irradiated with a narrowly focused electron beam, that is, the part of the sample surface that is to be analyzed. Since the ion-milled part is irradiated with the electron beam, it is possible to perform elemental analysis and shape observation of foreign substances contained in a deeper part of the sample than in the past, only in the ion-milled part.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that the same members as in FIG. 3 are given the same reference numerals.

The scanning type microscopic X-ray analyzer shown in Fig. 1 includes an electron gun 3 that emits a finely focused electron beam 2 that irradiates a sample 1 placed in the air, and an electron gun 3 that emits a narrowly focused electron beam 2 that irradiates a sample 1 placed in the air. An X-ray detector 5 includes an X-ray spectrometer that selectively detects X-rays 4 of a specific wavelength, and a secondary detector 5 that detects secondary electrons 6 emitted from a minute portion of the sample 1 by irradiation with the electron beam 2. It is the same as the conventional device in that it has an electron detector 7, but an ion milling device 9 is particularly provided, whereby the sample 1 to be irradiated with the electron beam 2 is irradiated with a finely focused ion beam 10. The irradiated portion is configured to undergo ion milling.

Using the device configured in this way, the ion milling device 9
When the ion beam 10 focused by the ion beam 10 is irradiated onto a minute portion of the sample 1, the irradiated portion is ion milled to form a minute recess 1a on the surface of the sample 1, as shown in FIG.

Next, when the recess 1a of the ion-milled sample 1 is scanned and irradiated with a narrow focused electron beam 2, X-rays of a specific wavelength are emitted from the elements contained in the minute foreign matter l1 present at the bottom of the recess 1a. 4 and 2 specified by its shape
Secondary electrons 6 are respectively emitted. These X-rays 4 of specific wavelengths and secondary electrons 6 can be detected by the same means as the conventional methods, and the detected signals can be processed to perform elemental analysis of the substance contained in the foreign object and observation of the shape of the foreign object at the same time. .

〔Effect of the invention〕

According to the present invention described above, it is possible to perform elemental analysis of foreign matter contained in a deeper part than before and observation of its shape at the same time. Therefore, it is possible to investigate the element, shape, position, etc. of foreign particles from the surface to the inside of semiconductor devices, solid-state imaging devices, and other thin film stacked devices, which have been difficult to analyze in the past when foreign particles are inside the laminated film. This is an effective means for improving trade in the above-mentioned devices.

Further, since the ion milling device is provided integrally with the scanning type microscopic X-ray analysis device, ion milling operations and analysis operations can be performed efficiently in a short time.

Furthermore, since the sample is milled in the air, there is less air pollution and adhesion of foreign matter, allowing for precise analysis.

[Brief explanation of drawings]

Fig. 1 is an explanatory view of the main parts of an embodiment of the scanning type microscopic X-ray analyzer according to the present invention, Fig. 2 is a cross-sectional view of a sample ion-milled by the apparatus shown in Fig. 1, and Fig. 3 is a conventional FIG. 2 is an exploded view of a scanning type microscopic X-ray analyzer. DESCRIPTION OF SYMBOLS 1... Sample, 2... Electron beam, 3... Electron gun, 4... X-ray, 5... Xil detector, 6...
-Secondary electron, 7...Secondary electron detector, 8...Cathode ray tube oscilloscope, 9...Ion milling device, 10...Ion beam, 11...M object.

Claims (1)

[Claims] 1. A means of scanning and irradiating the surface of a sample to be analyzed with a narrowly focused electron beam, and of the X-rays emitted from the sample surface by the irradiation of this electron beam, X-rays of a certain wavelength
In a scanning microscopic X-ray analysis device, which has a means for selectively detecting a ray, and a means for detecting a shape in a microscopic part of a sample from secondary electrons emitted from a sample surface by irradiation with the electron beam, A scanning type microscopic X-ray analysis device, characterized in that the analysis device is provided with an ion milling device for ion milling a sample surface irradiated with the electron beam.