JPH0630233B2 - Surface analyzer - Google Patents

Description

The present invention relates to a sample, particularly a thin film sample, in an apparatus such as an EPMA (electron beam microanalyzer) for irradiating a sample with an electron beam for surface analysis. The present invention relates to a sample holding table that holds the.

(Prior Art) When measuring a thin film sample in a surface analyzer such as EPMA, the thin film sample is supported at its edge and the measurement part is held in a space, or held on a bulk sample holder.

(Problems to be Solved by the Invention) When the analysis sample is a thin film, the energy of incident electrons is relatively high and the ionization rate is small (see Chapter 4 of Dr. Hiroyoshi Soejima (Osaka University, 1979)).

As shown in FIG. 3, when the sample 1 is held in space, the electrons 4 of the incident electrons 2 that have passed through the sample 1 do not contribute to the ionization of the sample 1. Reference numeral 3 is an X-ray generated along with ionization. Further, as shown in FIG. 4, when the sample 1 is held on the bulk sample holder 5, some of the electrons 4 that have passed through the sample 1 are reflected by the sample holder 5 and the reflected electrons 6 are reflected. Then, it again enters the sample 1 and contributes to the ionization of the sample 1, but the degree of the contribution is not large.

As described above, in the case of a thin film sample, there are problems that the sample excitation efficiency is low, the intensity of the signal (X-ray in the case of EPMA) is small, and the detection sensitivity is low.

The present invention provides a surface analysis device that performs electron beam irradiation,
The purpose is to increase the analytical sensitivity of a thin film sample.

(Means for Solving Problems) The present invention is intended to solve the above problems by improving a sample holder, and the sample holder has at least a portion for holding a sample that penetrates a magnetic domain. The magnet is oriented so that the magnetic domain direction of the magnet is generally perpendicular to the direction of incidence of the electron beam, and the sample fixing surface of the magnet is such that the incident electrons transmitted through the sample The sample holder is installed so as to be tilted in the direction in which the sample is bent by the Lorentz force and returned to the sample.

(Function) Electrons that have passed through the thin film sample are bent by the Lorentz force due to the magnetic field from the magnet of the sample holder, and the proportion of the electrons that emerge from the surface of the magnet and enter the thin film sample again increases.

(Embodiment) FIG. 1 shows an embodiment. Reference numeral 7 is a sample holder made of a permanent magnet, and the thin film sample 1 is fixed on the surface. When the sample holder 7 is installed in a surface analyzer such as EPMA, the sample holder 7 is set in a direction perpendicular to the incident direction of the incident electrons 2.
Moreover, the surface of the sample holder 7 (the surface to which the thin film sample 1 is fixed) is installed so as to be inclined in the direction in which the incident electrons 2 are bent in the sample holder 7 by the Lorentz force. That is, in FIG. 1, assuming that the incident electrons 2 are incident from above, and the direction of the magnetic domains of the sample holder 7 is from the back surface to the surface with respect to the paper surface, the surface of the sample holder 7 is As shown in the figure, install it by inclining to the right from the horizontal. M
s indicates the state of magnetization.

When the thin film sample 1 is fixed to the sample holder 7 of the permanent magnet installed as shown in FIG. 1 and the electron 2 is irradiated, the incident electron 2 not only excites the thin film sample 1 but also penetrates the thin film sample 1. Most of the electrons receive Lorentz force in the sample holder 7 and are scattered toward the thin film sample 1, so that the probability of becoming the reflected electrons 6 that enter the thin film sample 1 again and excite the thin film sample 1 becomes high. . That is, the ionization rate of the incident electrons 2 is significantly improved.

FIG. 2 shows another embodiment. This sample holder is configured by embedding a permanent magnet 11 in a bulk portion 10 having no magnetism, and the thin film sample 1 is fixed to the surface of the permanent magnet 11.

The direction of the magnetic domains of the permanent magnet 11 and the direction of the surface inclination when the sample holder is installed in a surface analyzer such as EPMA are the same as those in FIG.

1 and 2, the direction of the magnetic domains of the permanent magnets 7 and 11 is most preferably at right angles to the incident direction of the incident electrons 2, but there is no practical problem even if they are slightly inclined. Therefore, the present invention includes such cases.

As still another embodiment, the permanent magnet shown in FIG. 1 or 2 may be an electromagnet.

(Effect of the Invention) According to the present invention, the electrons that have passed through the thin film sample receive the Lorentz force from the magnetic field of the magnet of the sample holder and enter the thin film sample again. The excitation efficiency of the thin film sample is improved and the detection sensitivity is improved as compared with the case of holding the sample or holding it on a sample holder that does not have magnetism.

[Brief description of drawings]

1 and 2 are sectional views showing an embodiment, respectively.
FIG. 4 and FIG. 4 are sectional views showing a conventional example. 1 ... Thin film sample, 2 ... Incident electron, 6 ... Reflected electron, 7, 11 ... Permanent magnet.

Claims (1)

[Claims] 1. A surface analyzer using an electron beam as an excitation source for a sample, comprising a sample holder on which a sample is fixed, and at least a portion of the sample holder which holds the sample is a magnet having a magnetic domain penetrating therethrough. The magnetic domain direction of the magnet is oriented almost at right angles to the incident direction of the electron beam, and the sample fixing surface of the magnet is such that the incident electrons transmitted through the sample are Lorentz force by the magnetic field in the magnet. A surface analysis device, which is installed so as to be inclined in a direction in which it is bent and returned to a sample.