JPS5968159A - Analyzer constituted by use of ion source - Google Patents

Abstract

PURPOSE:To prevent any shaded areas to be seen from an ion gun, and enable the analytic accuracy of depth direction to be greatly improved by causing the axis of an ion beam to coincide with that of an electron beam. CONSTITUTION:An ion-beam deflecting part 5 is installed in the middle of an electron-optical system through which an electron beam passes. An ion source 3 and a lens 4 are installed at the entrance along the axis of the ion beam. Owing to such a constitution, an ion beam produced from the ion source 3, after being controlled in its diameter and current by means of the lens 4, is introduced into the ion-beam deflecting part 5. In this deflecting part 5 working as a mass analyzer of primary ions, ions with a uniform mass number are allowed to pass and their traces are made to coincide with the axis of the electron beam. Since a magnetic field is effective in such a case, a sector mass generated by an electromagnet is used for the ion-beam deflecting part 5. A detector 9 is used to detect and analyze various kinds of information obtained from a sample, such as secondary electrons, secondary ions and Auger ions. Various kinds of detectors are used according to respective purposes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to an analysis device using an ion source, such as a secondary ion mass spectrometer, a surface analysis device using an electron beam, such as an Auger component spectrometer, etc. The present invention relates to new improvements to the device.

The secondary ion mass spectrometer uses a primary ion beam of argon, oxygen, cesium, etc. to the sample, and the secondary ions generated from the sample are sent to a J-purchase analyzer for elemental analysis of the sample. Find out the distribution in the depth direction of the specific element system.

What point on the sample do you want to analyze with conventional equipment? The decision was made after checking with an optical microscope. This method did not provide high magnification and was not suitable for rope analysis. For example, with improved performance, it has become possible to narrow down the primary ion beam and analyze an area of several microns, but with optical microscopes attached to conventional equipment, it is possible to analyze an area of several microns. ij: 0.1 = Only a resolution of about 0.01 ran can be obtained. This is because the device is an ultra-high vacuum device and cannot be optimally designed as an optical microscope.

Furthermore, when an ion beam and an electron beam are used together as an analyzer, various types of information can be exchanged, but in the past, the ion beam and the electron beam differed in the angle at which the sample was identified, posing problems as described below.

The present invention aims to provide an extremely effective means for quickly eliminating the above-mentioned drawbacks, and has a configuration in which the ion beam axis and the t-son beam axis are perfectly aligned. Compared to other cases, it has 7 characteristics.

A preferred embodiment of the analyzer will be described in detail.

In Fig. 2, an electron beam narrowed by an electron gun 1 and an electron lens 2 is irradiated onto a sample 8 through an objective lens 6 and a deflection electrode 7, and secondary electrons generated from the sample are observed. As a scanning electron microscope, it can be used to non-destructively observe the surface of a sample and determine measurement points, and it can also be used to measure the depth after deep-field analysis using an ion beam, which will be described later. An ion beam deflector 5 is provided in the middle of the electron optical system through which the ion beam passes, and an ion source 6 and a lens 4 are provided on this axis. On the other hand, the ion beam generated by the ion source 3 is guided to the ion beam deflection section 5 with the beam diameter, current, etc. controlled by the lens 4 (7)). Here, as a primary ion mass analyzer, an ion beam with a uniform mass number is generated and aligned with the electron beam axis. In this case, since the magnetic field is effective, the deflection part of the ion beam is the ridge value magnet VC! The sector mass f is used. Also, even if the deflection is performed using an electric field, it will not work, but in this case, it is necessary to provide a passage section 5a in addition to the deflection section 4, but in the case of a magnetic field, it is placed at a position 90 degrees out of phase with the case of the VC; , is not necessary for the passage section 5a. In addition, the deflection electrode 7 is used for a charged particle beam (son or ion) f 1lF6
The same method used in television is used to scan and scan a sample to obtain two-dimensional information from the sample. Detector 9
is sample J: Information on each ridge obtained, for example, secondary electrons, 2
A detector is used to detect and analyze all secondary ions, Auger electrons, etc., and various types of detectors are used depending on the purpose.

Some conventional secondary ion mass spectrometers are equipped with an electron gun independent of the primary ion optical system (Figure 1).
The purpose of these electron guns is to prevent charge-up due to primary ion irradiation when the sample is an insulator. For example, this electron gun'f! r: It is possible to achieve almost the same function as above by narrowing the aperture and scanning, but it has the following disadvantages: It is difficult to align the electron beam axis and the ion beam axis, as shown in Figure 1. If the height of the sample differs due to unevenness, the position where the electron beam hits the sample and the position where the ion beam hits the sample will be different, resulting in a shift between the observation and analysis positions.Also, parallax (haralax) will occur, which will prevent craters caused by the ion beam. If it is deep, there will be parts that become shadows and cannot be observed. In the present invention, since the electron beam and the ion beam are on the same axis, this problem is solved.

For example, as an application example of the device of the present invention, one of the surface analysis devices is scanning Auger Hiroko microscopy (S canning Auger microscopy).
ger Microecopy,), but in this case, the sample surface is irradiated with an electron beam and analyzed using an Auger electronic sound analyzer, which generates electrons from the sample surface. sample rlf
Etching with l'i ion beam. Conventionally, for this reason, all ions are irradiated from an oblique direction, so if there are irregularities on the surface, the shadow portion seen by the ion gun 1 remains unremoved, resulting in incorrect information being obtained for analysis in the depth direction. Even in this case, if the sample can be irradiated with an electron beam and an ion beam from a 10" axis as in the present invention, the analysis in the depth direction can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the shift of the irradiation point when the sample position moves up and down using a conventional device. Fig. 2 is an overall block diagram showing all the embodiments of the present invention. 1... Electron gun 2 ...Sample lens 6...Ion gun 4...Ion lens 5...Deflection electrode or V-type deflection magnetic pole 6...Objective lens 7...Scanning electrode 8...
Sample 9...(moxibustion device or higher)

Claims (3)

[Claims] (1) Equipped with an electron gun that generates an electron beam, an ion source that generates an ion beam, and means for deflecting the electron beam or the ion beam, or both, to direct the electron beam or the ion beam or both to the sample from the same axis. A device that is characterized by being able to irradiate at the same time. (2) An electron gun that generates an electron beam; 1. It is characterized by being equipped with an ion gun that generates all the ion beams and a means for deflecting the electron beam or ion beam or both, guiding the ion beam on the same axis as the electron beam, sharing an objective lens, and irradiating the sample with the beam. Analyzer for (3) An electron gun, an electron beam control means (electron optical system), and a sample are arranged in a straight line, a means for irradiating the entire electron beam, a means for deflecting the ion beam in the middle of the electron optical system, and a means for the deflection system. An analytical device that has an ion gun on its axis, uses a common objective lens, and irradiates the sample with an ion beam and an electron beam from the same axis. Alternatively, the arrangement of the electron source and the ion source can be swapped, the ion beam can be arranged intuitively, the electron beam can enter from the side of the ion optical system, be deflected, and the entire ion beam or electron beam can be irradiated onto the sample from the same axis. An analytical device with all the following characteristics.