JPS5825053A - Ion beam observation - Google Patents

Abstract

PURPOSE:To know the area of a sample which is analyzed with an ion beam by scanning an electron beam, which has a smaller diameter than an ion beam, over a sample upon which the ion beam is irradiated, and displaying the image of thus produced secondary electron beam. CONSTITUTION:An ion beam 5 sent from an ion source 1, after being restricted to be very fine, is irradiated upon a sample 4, and thus produced secondary ions are analyzed by a proper means. At this point, an electron beam 9 sent from an electron gun 6 is restricted to be much more fine than the ion beam 5, and is scanned over the sample 4 by means of a polarizing lens 8. Next, a secondary electron beam 11 given by the above scanning is detected with a secondary- electron detector 10, and sent to a cathode-ray tube 13 so as to display a secondary-electron image of the sample 4. As a result, since a part to which ions are applied is displayed within the image of the secondary electron beam 11, the analyzed area can be known from the diameter of the ion beam image. Besides, the position of the analyzed area can be known from the position of the ion beam image.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion beam observation method for determining the analysis area of a sample using an ion beam.

Recently, a sample Cζ has been irradiated with an ion beam, and the surface elements of the irradiated area have been analyzed from the generated secondary ions. If the diameter of the ion beam irradiated with this sample-ζ is large, the irradiation area becomes large and only the average properties of the sample can be determined, so it is effective for sample analysis-ζ to irradiate the sample with an ion beam of minute diameter.

By the way, when a sample is irradiated with a micro-diameter ion beam and the irradiated micro region is analyzed, it is necessary to know the size and position of the analysis region.

The present invention was developed in order to achieve such an objective, and the sample irradiated with a micro-diameter ion beam is scanned with an electron beam having a diameter of 1 smaller than the diameter of the incoming ion beam. This invention provides a new 111 & ion beam observation method in which the micro analysis area can be determined by displaying the me of the secondary electron beam. The present invention is based on the principle as described below.
Ru.

In other words, since the part of the sample that is hit by d and ions changes compositionally and chemically, the secondary electron yield when irradiating the sample with electron Isf also changes compared to the part that is not hit by ions. are doing. Therefore, by scanning a sample irradiated with a micro-diameter ion beam with an electron beam having a diameter smaller than that of the ion beam, the f of the secondary electron beam generated from above the sample is
If you look at ll, you will see the area where the -ζ ion hit.

Figure 1 shows a specific example of the ion beam observation method of the present invention. In Figure 1, 1 is an ion gun, 2 is a focusing lens,
Reference numeral 6 denotes a deflection lens, through which the ion beam 5 emitted from the ion gun 1 is narrowed down to a minute position and placed at an appropriate position on the sample 4.
ζ irradiation is performed, and the resulting secondary ions, for example, are analyzed by suitable means. Reference numeral 6 denotes an electron gun, 7 a focusing lens, and 8 a deflection lens.The electron beam 9 emitted from the electron gun 6 is focused to a smaller size than the ion beam 5, and is scanned over the sample 4 by the deflection lens 8. .

A secondary electron detector 10 detects a secondary electron beam 11 generated from the sample 4 and sends it to a cathode ray tube 13 via an amplifier 12. A scanning signal generator 14 sends scanning signals to the deflection lens 8 and the deflection lens 15 of the cathode ray tube 16 in synchronization.

Now, when the micro-diameter ion beam 5 is irradiated to an appropriate position on the sample 4, and at the same time the sample is scanned with the electron beam 9, which has an even smaller diameter than the ion beam, the screen of the cathode ray W15 appears on the screen of the sample 4. The next e-mail will be displayed. At this time, an ion beam image 16 based on the above-mentioned principle appears as shown in Figure 1 and f42 in the brocade secondary electron image. For example, when the sample is silicon, a blackish ion beam image appears.

Therefore, the analysis area can be determined from the diameter of this ion beam image, and the position of the analysis area can be determined from the position of the beam image.

[Brief explanation of the drawing]

FIG. IIIt1 shows a specific example of the ion beam wrinkle detection method of the present invention, and FIG. 2 is a diagram to supplement the explanation of its operation. 1: Ion gun, 2.7: Focusing lens, 6.8: Deflection lens, 4: Sample, 5: Ion beam, 6: Electron gun, 9: Electron beam, 1o: Secondary electron detector, 11: Secondary Electron beam, 15: Cathode ray tube. Patent applicant JEOL Ltd. Representative Tadao Kase

Claims (1)

[Claims] An ion beam observation method in which a sample irradiated with an ion beam is scanned with an electron beam of VS@ smaller in diameter than the ion beam, and the ion beam irradiation area on the sample is displayed.