JPH07134963A - Sample inclining device for electron microscope - Google Patents

Abstract

PURPOSE:To provide a sample inclining device by which a sample processed by a focusing ion beam can be efficiently observed by means of an electron microscope. CONSTITUTION:A sample inclining device for an electron microscope is constructed of a sample inclining device 3 installed in the electron microscope and a sample holder 7, which consists of an outer shaft 8 and an inner shaft 9 carrying a sample 17. In the external end of the outer shaft 8, a knob 13 rotating the inner shaft 9 is arranged, and by this knob 13, positioning of the processing position can be precisely carried out when the sample 17 is processed by a focusing ion beam device. In this way, the sample holder 17 can be used for both of the focusing ion beam device and the electron microscope, so that processing and observation of the sample can be carried out quickly, and the sample can be inclined at a large angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample tilting device for an electron microscope, and more particularly to a sample tilting device for efficiently observing a sample processed by a focused ion beam with an electron microscope.

[0002]

2. Description of the Related Art When observing a sample with an electron microscope, the thickness of the sample must be a thin film of 0.1 .mu.m or less (the thickness depends on the accelerating voltage of the electron beam) capable of transmitting an electron beam. Especially, in the case of a semiconductor sample, it is processed into a thin film by a focused ion beam device. When observing a sample processed with a focused ion beam with an electron microscope, the sample is replaced, and if it is observed with an electron microscope and the processing method is insufficient, the sample is re-tested. I have to replace them and reprocess them, which is very annoying. Further, in recent years, there is a tendency to pursue high-resolution observation, so that the pole piece gap of the objective lens becomes narrow, and it becomes difficult to tilt the sample at a large angle.

[0003]

SUMMARY OF THE INVENTION To process a sample into a thin film with a focused ion beam apparatus and then to allow observation with an electron microscope without performing a sample remounting operation,
Even if the processing with the focused ion beam is repeated, the observation with the electron microscope can be efficiently performed. Further, the sample should be observed with a large angle inclination even within the pole piece gap of the narrow objective lens.

[0004]

SUMMARY OF THE INVENTION In the present invention, a sample tilt including a center shaft on which a sample is placed and an outer shaft sharing a center with the center shaft, and a means for rotating the center shaft at a rear end of the outer shaft is provided. The device was made compatible with both the focused ion beam device and the electron microscope. When irradiating the ion beam with the focused ion beam device, the sample placed on the defect at the tip of the central shaft was rotated by 90 °, and when irradiating the electron beam with the electron microscope, the sample was inverted by 90 °. . Even if the above operation is repeated, the ion beam optical axis and the electron beam optical axis of the sample intersect at a right angle at the center of the center axis. Further, the rotation of the center axis is accurately positioned at an angle of 90 ° by the stopper. Therefore, the position can be easily reproduced. Further, coarse rotation, that is, sample inclination is given to the center axis, and fine movement rotation, that is, sample inclination is given to the outer axis, and both rotations are combined to enable large-angle inclination of the sample. This is because in the narrow objective lens pole piece gap, rotation of the outer shaft having a large outer diameter with respect to the outer shaft having a small outer diameter results in larger rotation, that is, a larger tilt angle. Further, the outer shaft is provided with a defect portion for taking out X-rays generated from the sample.

[0005]

According to the above construction, the sample can be inserted into the electron microscope for observation without being replaced, and the sample can be inserted into the electron microscope while being held as it is after being processed by the focused ion beam apparatus. Since the processing position and the observation position of the sample can be repeatedly reproduced by a simple procedure of 90 ° rotation, the processing and the observation can be repeated quickly. Also, ± 4 depending on the center axis
After performing coarse movement tilt of about 5 °, ± 15 ° by the outer shaft
If a slight movement tilt is performed, a large angle tilt of ± 60 ° becomes possible when combined. It is also possible to take out X-rays from the defective portion of the outer shaft and perform X-ray analysis.

[0006]

An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a sample tilting device 3 is attached to a wall 2 which constitutes a vacuum chamber 1 in an electron microscope sample chamber in a vacuum resistant manner. The sample tilting device 3 is composed of a base cylinder 3A, a spherical body part 4, a swinging rotary motion mechanism 5, and a rotating body 6, and rotates the rotating body 6 to tilt the sample. In the base cylinder 3A, a rotary body 6 that pivotally rotates about the spherical body portion 4 by a swinging motion mechanism 5 is inserted in a vacuum resistant manner. The sample holder 7 is composed of an outer shaft 8 having a hollow shaft shape and an inner shaft 9 sharing the center with the outer shaft 8. The sample holder 7 is arranged so as to be orthogonal to the electron beam optical axis 10 and passes through the rotating body 6 to outside the vacuum chamber 1. From the inside to the inside in a vacuum resistant manner. A thin plate portion 8 ', which is formed by cutting the top and bottom of the sample holder 7, that is, the outer shaft 8 and the center shaft 9,
9'is located between the upper pole piece 11 and the lower pole piece 12 of the objective lens. A knob 13 for rotating the center shaft 9 is provided in a hole 15 provided at the outer end of the outer shaft 8.
The positioning pin 14 fixed to the shaft engages with it, and the thin plate portion 9 ′ at the tip of the center shaft 9 is prevented from tilting. The hole 15
Are provided as needed, and two of them are provided at a pitch of 90 °. The thin plate portion 8 ′ at the tip of the outer shaft 8 has a defect 16 </ b> A and the thin plate portion 9 ′ at the tip of the center shaft 9.
The defective portion 16B is provided in the. Missing part 1 of central shaft 9
The sample 17 is fixed to the 6B with an adhesive or a spring, and the observation part 18 of the sample 17 is brought into contact with the sample positioning member 20 via the pivot 19 so that the observation part 18 of the sample 17 can be accurately positioned at the intersection of the electron beam optical axis 10. is doing. Next, the sample tilting device 3
An embodiment in which the above is mounted on a focused ion beam device will be described with reference to FIG. The sample tilting device 3 is attached to the wall 22 that constitutes the vacuum chamber 21 of the focused ion beam device sample chamber in a vacuum resistant manner. Details of the sample tilting device 3 and the sample holder 7 are omitted because they are as described above. A secondary electron detector 24 is attached to the other wall 22 ′ of the vacuum chamber 21 in a vacuum resistant manner, and an ion beam optical axis 25 passing through the objective lens 23 in the vacuum chamber 21 is orthogonal to the sample 17. There is. The operation of the sample tilting device having such a configuration will be described first by taking a sample preparation in the focused ion beam device as an example.

With the sample holder 7 inserted in the sample tilting device 3, the knob 13 for rotating the center shaft 9 is rotated 90 ° counterclockwise, and as shown in FIG.
The ion beam optical axis 2 with the defect 16B at the tip of the
Make it orthogonal to 5. The oscillating rotary motion mechanism 5 causes the defective portion 1
The sample 17 fixed to 6B is aligned with the ion beam optical axis 25 at right angles. The ions irradiated onto the sample are observed by the observation section 18 by sputtering the sample.
Can be processed. On the other hand, the electrons or ions emitted at the time of sputtering are detected by the secondary particle detector 24, and although not shown in the figure by this electric signal, CR
An image of the ion irradiation part is recorded on T. The processing position is accurately determined from this image, and the observation portion 18 of the sample 17 is processed so as to form a thin film of 0.1 μm or less. Sample 1 after processing
The sample holder 7 is pulled out together with the sample holder 7 and inserted into the sample tilting device 3 attached to the electron microscope. The electron microscope is made ready for observation by a predetermined procedure. Next, the central shaft 9
Rotate the knob 13 to rotate 90 degrees clockwise,
As shown in FIG. 2 (a), the defective portion 16B at the tip of the center shaft 9 is made horizontal. The observation part 18 of the sample 17 is the electron beam optical axis 10.
Since it is orthogonal to, the electron beam can be transmitted through the thin film portion for observation. When the observation section 18 of the sample 17 is irradiated with an electron beam, X-rays are generated, but the X-rays can be taken out from the defective portion 16A at the tip of the outer shaft 8 for X-ray analysis. Since the sample can be mounted on both the focused ion beam device and the electron microscope without performing the remounting work in this way, even when reworking is performed quickly, the observation efficiency becomes very good. Next, observation of a large-angle tilt of the sample with an electron microscope will be described. With respect to the horizontal state of the observation unit 18 of the sample 17, the knob 13 for rotating the center shaft 9 is rotated in the plus direction or the minus direction at a pitch of 5 ° to 10 °, and the sample 17 is coarsely moved at a pitch of 5 ° to 10 °. Inclining dynamically. If holes 15 are provided at the outer end of the outer shaft 8 at this pitch, positioning can be performed easily. Furthermore,
If the outer shaft 8 is finely tilted and combined, observation at a large angle tilt can be performed. If the gap between the upper pole piece 11 and the lower pole piece 12 of the objective lens is set to about 5 mm and the outer diameter of the outer shaft 8 is set to about 8 mm, it is possible to incline ± 15 ° and the outer diameter of the middle shaft 9 is set to the diameter. If it is about 5 mm, it is ± 45
Tilt is possible, and when combined, a large angle tilt of ± 60 ° is obtained. Since the outer diameter end faces of the outer shaft 8 and the center shaft 9 are chamfered as necessary, they do not come into contact with the pole pieces.

[0008]

As described above, according to the present invention, the following effects can be achieved.

(1) The sample holder can be shared by the focused ion beam device and the electron microscope.

(2) The sample position at the time of processing and at the time of observation can be switched with one touch, and positioning can be performed accurately.

(3) Since the processing and the observation can be performed without performing the sample remounting work, the repeated processing and the observation can be quickly performed.

(4) Since there is no sample remounting work, handling is simple and troubles such as sample damage due to carelessness can be prevented.

(5) Since it is not necessary to provide a passage for passing the ion beam on the outer shaft, the mechanical strength can be maintained.

(6) Since the structure in which the sample is fixed is not strained by atmospheric pressure, drift due to strain does not occur.

(7) A large angle tilt of the sample can be realized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a sample tilting device for an electron microscope showing an embodiment of the present invention.

FIG. 2 (a) Observation direction of the main part of the sample holder in FIG.
(b) It is an enlarged plan view of the processing direction.

FIG. 3 is a longitudinal sectional view of a main part of a focused ion beam device showing an embodiment of the present invention.

[Explanation of symbols]

1, 21 ... Vacuum chamber, 3 ... Sample tilting device, 5 ... Swing rotation movement mechanism, 7 ... Sample holder, 8 ... Outer shaft, 9 ... Middle shaft, 10
... Electron beam optical axis, 11, 12 ... Pole piece of objective lens, 16A, 16B ... Defect portion, 17 ... Sample, 18 ... Observation portion, 23 ... Objective lens, 24 ... Secondary particle detector, 25 ...
Ion beam optical axis.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidemi Koike 882 Ichige, Ita, Katsuta, Ibaraki Hitachi Ltd. Measuring Instruments Division (72) Inventor Kie Yaguchi 832 Nagakubo, Horiguchi, Katsuta, Ibaraki Prefect. Measurement Engineering Co., Ltd.

Claims (7)

[Claims] 1. A sample holder on which a sample is mounted is rotatably inserted from a direction orthogonal to an electron beam optical axis, and a sample is moved by moving the sample holder in an axial direction while maintaining airtightness with a vacuum seal. In the apparatus as described above, the sample holder is composed of an inner shaft on which a sample is placed and an outer shaft sharing a center with the inner shaft, and a means for rotating the inner shaft is provided at a rear end of the outer shaft to incline the sample. A sample tilting device for an electron microscope, which is capable of performing the following. 2. A large-angle tilt of a sample can be performed by giving a rotation of coarse movement to the center axis and a rotation of fine movement to the outer axis, and combining both rotations. The sample tilting device for an electron microscope according to claim 1. 3. The sample tilting device for an electron microscope is configured so that it can be mounted on a focused ion beam device, and the sample holder can be used for both the focused ion beam device and the electron microscope, and the focused ion beam is processed. The sample tilting device for an electron microscope according to claim 1, wherein the sample can be observed by an electron microscope without remounting the sample. 4. A defect portion for irradiating a sample with an ion beam is provided on the central shaft, and a defect portion for taking out X-rays generated from the sample is provided on the outer shaft. The sample tilting device for an electron microscope according to any one of claims 1 to 3. 5. The ion beam optical axis of the sample and the electron beam optical axis of the sample are configured so as to intersect at a right angle at the center of the center axis. The sample inclining device for an electron microscope according to. 6. When irradiating an ion beam with the focused ion beam apparatus, the center shaft is rotated by 90 °, and when irradiating the electron beam with the electron microscope, the center shaft is rotated by 90 °.
2. The structure according to claim 1, wherein the structure can be inverted.
6. The sample tilting device for an electron microscope according to any one of items 1 to 5. 7. The rotation of the center shaft is positioned at an angle of 90 ° by a stopper so that it can be accurately reproduced even if the ion beam irradiation position and the electron beam irradiation position are repeatedly switched. 7. The sample tilting device for an electron microscope according to any one of 1 to 6.