JPS6062048A - Electron ray macro analyzer - Google Patents

Abstract

PURPOSE:To prevent lowering of sensitivity of the captioned device by making the making the constitution that a copper plate and a semiconductor plate composing a detector of reflected electrons are provided, being allowed to be superposed on each other in two layers, and when the electron ray beam is strong, the copper plate is placed in the position under the semiconductor plate. CONSTITUTION:In the case of carrying out analysis with high sensitivity, for example, when a large current of 100muA at 20KV is supplied to a electron gun, evaporation is caused on the surface of a specimen 7 because the electron ray beam 4 radiated on the surface of the specimen 7 is strong. When the molecules of the specimen 7 melted by heat scatter and stick to the lower surface of a semiconductor plate 9, the sensitivity of a semiconductor plate 9 as the detector of the reflected electrons is lowered and therefore a copper plate 10 is placed is placed in the position under the semiconductor plate 9 by driving a motor 13 in order that the scattering molecules of the specimen 7 on evaporation is received by the copper plate 10 and the detection is carried out without allowing the scattering molecules to stick to the semiconductor plate 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam macro analyzer for surface analysis of iron plates, etc., and particularly relates to a novel improvement for irradiating a high-current electron beam for high-sensitivity analysis. .

There are various conventional electron beam macro analyzers of this type, but all 7L use a semiconductor plate as a backscattered electron detector. As a result, the surface of the sample undergoes evaporation and adheres to the back surface of the semiconductor plate, reducing the sensitivity of the backscattered electron detector over a long period of time. This results in extremely low sensitivity during normal analysis using this method.

In particular, an electron beam source for outputting an electron beam, and an electron lens provided adjacent to the electron beam source to convert the electron beam from the electron beam source into a beam of a predetermined diameter. An electronic scanning coil is provided in contact with the electronic lens to scan the electronic beam by reciprocating at a certain angle. Provided in contact with A rL
A backscattered electron detector is provided for detecting backscattered electrons from the sample when the sample is irradiated with the fi ray beam, and a copper plate and a semiconductor plate are included in the backscattered electron detector, and the copper plate and the semiconductor plate are in contact with each other. If the electron beam is strong, the copper plate will be polymerized in the lower layer of the semiconductor.
The structure is designed to make it look like this.

μ Below, in the drawings that explain in detail preferred embodiments of the electron beam macro analyzer according to the present invention, the reference numeral 1 designates an electron gun as an electron beam source.
The electron beam emitted from the electron gun 1 is controlled 1 by an 1Lfc electron lens 2 and a scanning coil 3 provided at a lower position of the electron gun 1.

That is, the electron lens 2 electronically controls the beam to have a predetermined diameter, and the scanning coil 3 controls the beam in a constant width direction (
The electron beam 4 passing through the scanning coil 3 is formed at the center of the backscattered electron detector 5. The light passes through the guide port 6 and is irradiated onto the surface of the sample 7.

When the electron beam 4 irradiated onto the sample 7 irradiates and scans the surface of the sample 7 over a certain range, backscattered electrons 8 are generated from the surface of the sample 7, and the backscattered electrons 8 are detected by the detector 5. The element distribution state on the 7 planes can be detected 2'.

The detector 5 is shown in FIG. 3 and is composed of a semiconductor plate 9 and a copper plate 10, with the semiconductor plate 9 being fixed to the main body (not shown) and shown in FIG. It consists of a pair of fan-shaped semiconductor pieces 9a and 9b which are integrally constructed so as to be folded over and fixed at a fixed position at the time.

The copper plate 10 is formed integrally with the semiconductor pieces 9α and 9b in a fan shape having the same shape as #1! copper plate piece 10α
and 10 b, and as shown in FIG. n
The cylindrical support 11 is rotatably provided coaxially within a support 12 that supports the semiconductor board 9, and a rotary gear 15 is provided on the rotating shaft 14 of a motor 13 fixed to the support 12. C is engaged with the gear portion 11α of the cylindrical support 11, and by rotating the motor 13, the copper plate 10
can be rotated in the direction of the arrow.

The motor 13 of b11 employs a guard motor and is controlled by an electronic circuit (not shown).
The rotating gear 15 and the gear portion 1 are arranged so as to overlap in a layered manner at a lower position of the semiconductor board 9, that is, at a lower layer position.
A diameter of 1α is designed.

In the above-described configuration, it is difficult to operate the electron beam macro analyzer according to the present invention.

First, when performing high-sensitivity analysis, the electron gun is powered at 20KV.
When a large current of I Q QμA is supplied, the sample 7 is
When the surface of evaporates and the 70 molecules of the sample melted by the heat scatter and adhere to the lower surface of the semiconductor board 9,
Since the sensitivity of the semiconductor plate 9 as a backscattered electron detector decreases, as shown in FIGS. 1 and 4, the motor 13
The copper plate 10 is superimposed on the lower layer of the semiconductor plate 9 by driving the copper plate 10, and the scattering of molecules of the sample 7 during evaporation is received by the plate 10, so that the scattering of the molecules onto the semiconductor plate 9 is carried out. Detection is done in a way that prevents it from adhering.

Also, in normal analysis, 20KV, lμA ~ 0゜01μ
In the case of the power source A, the reflected electrons 8 are 0°01μA to 0°000'lμA, so the motor 13
The copper plate 10 is rotated so that the copper plate 10 and the semiconductor plate 9 do not overlap with each other as shown in FIG. 2, and the reflected electrons 8 are detected by directly hitting the semiconductor plate 9.

Since the electron beam macro analyzer according to the present invention has the above-described configuration and function, it is possible to prevent a decrease in the sensitivity of the semiconductor detector, especially when performing high-sensitivity analysis using a large current. It enables highly sensitive sample surface distribution analysis at both low and high currents.

[Brief explanation of drawings]

The drawings show an electron beam macro analyzer according to the present invention. Fig. 1 is an overall configuration diagram, Fig. 2 is a plan view showing a state in which the semiconductor plate and copper plate of the detector do not overlap with each other, and Fig. 3 is a diagram of the detector. The cross-sectional view and FIG. 4 are plan views showing a state in which the semiconductor plate and the copper plate of the detector are superimposed on each other. 1 is an electron gun as an electron beam segment, 2 is an electron lens, 3 is a scanning coil, 4 is an electron beam, 5 is a backscattered electron detector, 6
is the guide 11, 7 is the sample, 8 is the reflected electron, 9 is the semiconductor plate, 9cL, 9b is the semiconductor plate piece, 10 is the copper plate, 10α,
1(] b is a copper plate piece, 11 is a cylindrical support part, 11α is a gear part, 12 is a support body, 13 is a motor, 14 is a rotating shaft, 15
is a rotating gear. Applicant Daini Seikosha Co., Ltd. Agent Bentarashi Mogami Tsutomu No. 11 Fuchi No. 21 Complete j', 3'g,;

Claims (1)

[Claims] An electron beam source for outputting an electron beam and this electron υ
In order to convert the electron beam from the source into a beam of a predetermined diameter, an electron lens is provided adjacent to the electron beam source, and an LrL electron beam is provided adjacent to the electron lens, and the electron beam is reciprocated at a predetermined angle. an electron scanning coil for scanning; a backscattered electron detector installed adjacent to the electron scanning coil to detect reflected electrons from the sample; The copper plate and the semiconductor plate are provided so as to be superimposed on each other in a two-layered form, so that when the electron beam is strong, the copper plate is superimposed on the lower layer of the semiconductor board. An electron beam macro analyzer characterized by the following configuration.