JP5492105B2 - Sample preparation equipment - Google Patents

Description

  The present invention relates to a sample preparation apparatus for preparing a sample observed with a scanning electron microscope or a transmission electron microscope.

  As an apparatus for preparing a sample observed with a scanning electron microscope (SEM) or a transmission electron microscope (TEM), for example, a sample preparation apparatus using an ion beam as described in Patent Document 1 is known.

  As shown in FIG. 4, this sample preparation apparatus is an apparatus that performs etching by irradiating the sample 101 with an ion beam IB emitted from an ion beam source, and forms a sample cross section suitable for observation by SEM or TEM. . In this sample preparation apparatus, a shielding plate 102 having straight side edges (edge portions) is disposed on the sample 101, and the sample exposed from the edge portion of the shielding plate 102 is etched by the ion beam IB. The sample 101 is configured to be processed. Since the portion of the sample 101 exposed from the shielding plate is scraped off by the ion beam, a flat sample cross section is formed along the linear edge portion of the shielding plate 102.

  A sample 101 manufactured using such a sample manufacturing apparatus is set in an SEM or a TEM, and an electron beam is irradiated onto a cross section that appears by etching, and observation is performed.

JP 2005-037164 A JP 2009-025243 A

  In the sample preparation apparatus described above, the shielding plate 102 is supported by the support member 103 that is supported on the base end side and has the distal end side as a free end. Then, the ion beam IB is applied to an edge portion of the shielding plate 102 toward the tip of the support member 103, and the sample 101 is processed along this edge.

  At this time, in this sample preparation apparatus, since the irradiation with the ion beam IB takes a long time of several hours or more, the shielding plate 102 is heated by receiving the irradiation with the ion beam IB and becomes a high temperature. Since the heat is transmitted to the support member 103 and the temperature of the support member 103 also rises, the support member 103 undergoes thermal expansion. When the support member 103 is thermally expanded, the shielding plate 102 moves in a direction away from the base end side as indicated by an arrow a in FIG. 4, so that the edge irradiated with the ion beam IB approaches the ion beam IB. It is gradually moved in the direction (the direction in which the region where the ion beam has been irradiated so far is hidden).

  When the shielding plate 102 moves in this manner, the region that was originally etched in the sample 101 is covered with the shielding plate 102 and is not etched. For this reason, there is a problem in that a good sample cross-section that has been cut with a knife does not appear and a good cross-sectional sample cannot be produced.

  As a countermeasure, Patent Document 2 proposes a structure in which a second support member is attached so as to be folded back at the tip of the support member 103 and a shielding plate is attached to the tip of the second support member. In the structure proposed in Patent Document 2, the movement of the shielding plate due to the thermal expansion of the support member 103 is prevented by making the thermal expansion coefficient of the second support member larger than the thermal expansion coefficient of the support member 103. The movement of the canceling shielding plate can be prevented by the thermal expansion of the support member.

  However, in such a proposed structure, it is inevitable that the structure is complicated, and it is necessary to select a material in consideration of the coefficient of thermal expansion, and there is a problem that the degree of freedom in design becomes narrow.

  The present invention is proposed in view of the above-described circumstances, and an object of the present invention is to provide a sample preparation apparatus that can solve the problems of the conventional apparatus and the proposed apparatus with a simple structure. .

In order to solve the above-described problems and achieve the above object, the sample preparation apparatus of the present invention arranges the shielding plate so that a part of the sample is exposed and the other is shielded, and straddles the shielding plate and the exposed part of the sample. In this way, a sample preparation apparatus for producing a cross section of a sample by etching an exposed portion of the sample by irradiating the sample with an ion beam, the base end portion being supported by the shielding plate stage and the shielding plate stage, A support member having a free end on the side, and a shielding plate supported on a distal end side of the support member, wherein the support member has a side edge toward the base end side of the support member of the shielding plate. The ion beam to a portion exposed from one side edge of the shielding plate of the sample installed at a position where the ion beam is shielded by the shielding plate by holding the shielding plate so as to be a beam irradiation position. Processing by And a light receiving means for receiving light from the sample cross section for observing the sample cross section from the shielding plate stage side is disposed on the opposite side of the sample cross section across the shielding plate stage, and the light receiving means Further, an observation hole serving as an optical path through which light from the cross section of the sample enters is provided in the shielding plate stage.

  In the sample preparation apparatus according to the present invention, the base end is supported by the shielding plate stage, the shielding plate is supported on the distal end side of the support member whose distal end is a free end, and the base of the support member of the shielding plate is supported. The shielding plate is held so that one side edge toward the end side is the irradiation position of the ion beam, and one side of the shielding plate of the sample installed at a position where the ion beam is shielded by the shielding plate Processing with the ion beam is performed on a portion exposed from the edge.

  Therefore, in this sample preparation device, the support member is heated by receiving heat generated by the irradiation of the ion beam to cause thermal expansion, and even if the shield plate moves, the base end of the support member of the shield plate Since the ion beam is radiated to one side edge toward the side, the shielding plate is moved away from the ion beam.

  Therefore, in this sample preparation apparatus, during processing of the sample by the ion beam, the region that was originally processed does not become unprocessed, and a sample with a good cross section can be manufactured.

It is sectional drawing which shows the structure of the sample preparation apparatus which concerns on this invention. It is the top view and sectional drawing for demonstrating the relationship between the shielding board stage 9, the shielding board 8, and the sample 6 in FIG. It is an exploded view for demonstrating the support structure of the shielding board 8 by the supporting members 22 and 22. FIG. It is a figure which shows the structure of the conventional sample preparation apparatus.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of a sample preparation apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a vacuum vessel, which is evacuated by a vacuum pump (not shown) through an exhaust port 2, and the internal space is maintained in a vacuum. Reference numeral 3 denotes an L-shaped rotary tilting table accommodated in the vacuum vessel 1, which is attached to one end of a rotary shaft 4 that penetrates the partition wall of the vacuum vessel 1 from the atmosphere side and is introduced into the inside. It is reciprocally rotated by a motor 5 connected to the other end of the rotating shaft 4.

  A sample stage 7 that holds and moves the sample 6 is placed on the rotary tilt table 3. The sample stage 7 includes a pedestal on which a sample is placed, holds a shielding plate 8, and a shielding plate stage 9 for overlapping the shielding plate 8 on the sample 5 so that a part of the sample is exposed and the others are shielded. Is attached.

  An ion gun 10 is attached to the upper part of the vacuum vessel 1. As this ion gun, a gas ion gun can be used. For example, a gas ion gun that generates Ar ions by ionizing Ar gas by discharge can be used. The ion beam IB having a relatively large diameter generated from the ion gun 10 is irradiated across the sample 6 and the shielding plate 8 stacked thereon. As a result, the portion of the sample 6 exposed from the shielding plate 8 is scraped by the ion beam, and a sample cross section along the edge of the shielding plate 8 is formed.

  Since the height of the sample on the sample stage 7 is set so that the rotation center 0 of the rotation shaft 4 passes through the processed portion by the ion beam IB, the ion beam IB is incident on the sample 6 and the shielding plate 8. The angle is repeatedly changed with the reciprocating rotation of the rotary tilt table 3. This repeated change in the incident angle gives an effect of eliminating streak-like irregularities generated in the cross section when the incident angle is not changed.

  The shielding plate stage 9 is perforated so as to penetrate the shielding plate stage 9 along the rotation center 0 in order to observe a sample cross section formed by processing with the ion beam IB from a direction perpendicular to the cross section. A sagging observation hole 11 is provided. An observation window 12 is provided on the wall surface in the extending direction of the observation hole 11 of the vacuum vessel 1, and an observation means 13 such as a CCD camera for observing a cross section of the sample through the observation window 12 and the observation hole 11 is outside the vacuum. Is arranged. Reference numeral 14 denotes a glass plate disposed in front of the observation window 12 in order to prevent scattered substances generated by the ion beam processing from adhering to the observation window 12, and can be exchanged for the end of the rotary tilt table 3. It is attached.

  2 is a plan view (FIG. 2A) and a cross-sectional view (FIG. 2B) for explaining the relationship among the shielding plate stage 9, the shielding plate 8, and the sample 6 in FIG. In both figures, the shielding plate stage 9 includes a base 20 attached to the sample stage 7, a slider plate 21 held on the base 20 so as to be movable in the direction indicated by the arrow X, and a base end side. It has a pair of support members 22 and 22 supported by the slider plate 21 and having a free end at the front end side. These support members 22 and 22 are integrated on the base end side, and the front end sides are configured to be parallel to each other, and a long plate-like shielding plate 8 is attached so as to pass to the front end side. These support members 22 are supported on the slider plate 21 so as to be movable in the direction indicated by the arrow Y in the figure. Accordingly, the support members 22 and 22 are movable in the X and Y biaxial directions on the sample stage 7.

  That is, the support members 22 and 22 are supported by the slider plate 21 on the base end side via the first linear bearing 27. The slider plate 21 is supported by the base 20 via a second linear bearing 28 orthogonal to the first linear bearing 27. And the rack part 24 which the adjustment pinion gear 23 provided in the base 20 side meshed | engaged is provided in the base end side of the supporting members 22 and 22. As shown in FIG. By rotating the adjustment pinion gear 23, the support members 22 and 22 are moved in the length direction of the shielding plate indicated by the arrow Y in the figure.

  The slider plate 21 is in contact with the tip of an adjustment screw 26 screwed into the base 20. When the adjustment screw 26 is rotated, the support member 22 is moved and operated together with the slider plate 21 in a direction orthogonal to the length direction of the shielding plate indicated by the arrow X in the drawing. The slider plate 21 is urged toward the distal end portion of the adjustment screw 26 by an urging member (not shown), and is prevented from being separated from the distal end portion of the adjustment screw 26.

  A rectangular shielding plate 8 is attached to the front ends of the support members 22 and 22 so as to be passed between the support members 22 and 22. The shielding plate 8 is supported by support members 22 and 22 so that the ion beam IB is incident on the surface at approximately 90 degrees. These support members 22 and 22 hold the shielding plate 8 with the one side edge (edge portion) 8a toward the base end side of the supporting members 22 and 22 of the shielding plate 8 as the center irradiation position of the ion beam IB. The relative position between the shielding plate 8 and the ion beam IB (and the sample) is adjusted by moving the support members 22 and 22 on the base 20 in the X and Y 2 axis directions.

  A sample 6 is placed at a position where the ion beam IB is shielded by the shielding plate 8. The sample 6 is placed on a pedestal provided on the sample stage 7 and is placed in a state where the upper surface portion is covered by the shielding plate 8. The ion beam IB is irradiated over the portion exposed from the one side edge 8a of the shielding plate 8 and the sample 6 with the one side edge 8a of the shielding plate 8 as a central irradiation position, and is shielded by the sample shielding plate by the ion beam IB. The exposed portion is processed while the processing of the portion is prevented.

  FIG. 3 is an exploded view for explaining the support structure of the shielding plate 8 by the support members 22 and 22. As shown in the drawing, the front end portion of the support member 22 is thinned, and the end portion of the thinned shielding plate 8 is overlapped on that portion. Furthermore, after the leaf spring 31 and the pressure plate 32 are stacked thereon, the pressure plate 32 is attached to the support member 22 with screws 33.

  In the above configuration, when the ion beam IB processing is started, the heat of the shielding plate 8 heated by the irradiation of the ion beam IB is transmitted to the support members 22 and 22 and heated. When thermal expansion occurs due to the temperature rise of the supporting members 22 and 22, the shielding plate 8 moves in the direction toward the free ends of the supporting members 22 and 22 indicated by the arrow B in FIG. 2B, that is, the ion beam IB. In contrast, the exposed portion of the sample is moved in the increasing direction.

  Therefore, in this sample preparation apparatus, during the processing of the sample 6 by the ion beam IB, the exposed portion of the sample is reduced with respect to the ion beam IB of the shielding plate 8 that blocks the ion beam IB, and the already processed portion is reduced. Movement in the direction of hiding is prevented. For this reason, a new part on the sample 6 is processed by the ion beam IB, and a sample in which a good cross section appears can be manufactured.

  As described above, in the present invention, the shield plate is adopted by adopting a simple structure in which the opposite edge (one side edge) of the shield plate is used for cross-sectional preparation as compared with the conventional example shown in FIG. Even if the supporting member that supports is thermally expanded, a sample having a good cross section can be produced. Compared to the above-described proposed apparatus, not only the second support member is unnecessary, but also an effect that selection of a material in consideration of the thermal expansion coefficient is unnecessary.

  In addition, in this sample preparation apparatus, the observation hole 11 is provided so as to penetrate the shielding plate stage 9 (specifically, the slider plate 21) along the rotation center 0. The sample 6 being processed can be observed with a CCD camera or a microscope.

1: Vacuum container 6: Sample 7: Sample stage 8: Shield plate 9: Shield plate stage 10: Ion gun 11: Observation hole 12: Observation window 13: Observation means 20: Base 21: Slider plate 22: Support member 23: Adjustment pinion gear 24: Rack portion 27: First linear bearing 28: Second linear bearing

Claims (1)

The shielding plate is arranged so that a part of the sample is exposed and the others are shielded, and the sample is irradiated with an ion beam so as to straddle the shielding plate and the exposed part of the sample, thereby etching the exposed part of the sample. A sample production apparatus for producing a cross section,
A shielding stage,
A support member whose base end is supported by the shielding plate stage and whose front end is a free end;
A shielding plate supported on the front end side of the support member,
The support member holds the shielding plate so that one side edge of the shielding plate toward the base end side of the support member is an irradiation position of the ion beam,
While performing the processing with the ion beam to a portion exposed from one side edge of the shielding plate of the sample installed at a position where the ion beam is shielded by the shielding plate ,
In order to observe the sample cross section from the shielding plate stage side, a light receiving means for receiving light from the sample cross section is disposed on the opposite side of the sample cross section across the shielding plate stage,
A sample preparation apparatus , wherein an observation hole serving as an optical path through which light from the sample cross section enters the light receiving means is provided in the shielding plate stage .

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