JP2009098088A - Sample preparing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample preparing method for preparing a sample suitable for an observation in a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). <P>SOLUTION: An adhesive 34 is applied to a substrate 30. Spacers 31, 32 are disposed and adhered so as to put a specimen 40a between them on the substrate 30. A laminated body is formed by applying the adhesive on the adhered specimen 40a and the spacers 31, 32 and sticking a transparent protection film 33. After the adhesive is cured, the laminated body is cut with a cutter. The cut specimen 40a sticks to a glass plate. The sample is prepared by grinding the laminated body to a predetermined thickness. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sample preparation method, and more particularly to a sample preparation method for preparing a sample suitable for observation with a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM).

  First, the principle and basic operation of the ion slicer will be described. FIG. 3 is a diagram illustrating the configuration of the ion slicer. In the figure, reference numeral 1 denotes a sample chip (sample piece), which is not shown, but is set in an IS (ion slicer) holder. The sample chip 1 is irradiated with an ion beam from the ion source 2 to the set sample chip 1. As shown in the figure, the ion source 2 can be tilted to ± 6 ° with respect to the optical axis 3. The sample chip 1 can be etched from both the front and back sides.

  Reference numeral 4 denotes a shield belt provided to isolate the front surface and the back surface of the sample chip 1. As shown in the figure, the shield belt 4 is wound around a plurality of pulleys 5 and can move in either direction. When the sample chip 1 is irradiated with an ion beam, the shield belt is also etched. Therefore, the used belt portion is moved and etched with a new belt portion. After such a movement of the belt is completed, the shield belt (hereinafter simply referred to as a belt) 4 is replaced. Reference numeral 6 denotes a CCD camera for observing the etched sample surface.

  Reference numeral 10 denotes an axis of a belt surface including the sample chip 1, and this belt surface can be tilted by ± 30 ° about the axis 10. The operation of the ion slicer configured as described above will be described as follows.

  As shown in FIG. 3, the ion slicer irradiates argon (Ar) ions from both sides to a sample chip 1 polished in a plate shape via a belt 4 as a shielding material, and thins the sample by an ion etching effect. It is. The ion source 2 can be locked up to ± 6 °. Then, argon ions are irradiated from both sides of the sample chip 1. Since this apparatus uses the belt 4 as a shielding material to irradiate the sample chip 1 with argon ions at a low angle, it can produce a thin film sample with a larger area and less damage than the conventional ion rimming (etching) method.

  In addition, a mechanism is provided for simultaneously locking the sample chip 1 and the belt 4 by ± 30 ° so that the ion-etched surface is as uniform as possible. As described above, not only the sample chip 1 but also the belt 4 are etched by ion beam irradiation. For this reason, in order to prevent the belt 4 from being cut, a new belt surface can be used by the rotation mechanism. This movement of the belt surface is performed at the operator's discretion. The etched surface of the sample chip 1 can be photographed with a CCD camera 6 placed in front of the sample chip 1 and viewed on a display such as a CRT.

  The size of the sample chip is, for example, about 0.5 mm × 2.5 mm × 0.1 mm as shown in FIG. In this case, it is necessary to cut out by a method according to the material of the sample chip 1. The cut sample chip 1 is fixed to a sample holder (IS holder) of an ion slicer with wax.

  FIG. 4 is an enlarged view of a portion etched by an ion beam. The same components as those in FIG. 3 are denoted by the same reference numerals. The sample chip 1 is etched by an ion beam, and the entire surface is removed as shown in the figure. Eventually, a hole (perforation) 15 as shown in the figure may open.

  FIG. 5 is an explanatory diagram of the milling process of the sample chip. 3 and 4 are denoted by the same reference numerals. First, as shown in (a), the state in which the sample chip 1 is divided into left and right by the shield belt 4 is the initial state. From this state, the ion beam is irradiated to the sample chip 1 from the left and right direction of the sample chip. Then, the region irradiated with the ion beam is etched and narrowed. Eventually, perforations (holes) 15 are opened in the sample chip 1. The thin piece sample formed at this time can be placed on, for example, a TEM sample stage to obtain a TEM image of the thin piece sample.

  FIG. 6 is an explanatory diagram of a basic sample cutting method of the ion slicer. First, as indicated by a circle 1, a sample material (Specimen) 20 that should be referred to as an original sample is cut with a diamond cutter blade 21. When the sample material 20 is cut at a predetermined interval by the diamond cutter blade 21 as shown by a circle 2, the sample material 20 is divided into units as shown by 20a. When this sample unit 20a is polished (polished) from both sides as indicated by circle 3, a sample chip 1 as indicated by circle 4 is obtained. This sample cutting method is a standard method applied to sufficiently large metals, ceramics, minerals, semiconductor materials and the like.

  FIG. 7 is a diagram showing a dimension example of the obtained sample chip 1. The thickness W1 is 0.1 mm, the width W2 is 0.5 mm, and the length W3 is 2.5 mm. If it is a magnitude | size of this grade, it can set to an ion slicer with an IS holder.

In this type of conventional technology, several auxiliary pieces are arranged along the outer periphery of the sample, surrounded so that a predetermined portion of the sample is exposed, and resin is embedded in the entire periphery of the sample to be cured, and the sample and A technique is described in which after the auxiliary piece is integrated and the predetermined portion is polished, the resin and the auxiliary piece are peeled off from the sample (for example, see Patent Document 1).
JP-A-11-160211 (paragraphs 0010 to 0022, FIGS. 1 to 3)

  In the conventional technique described above, there is a problem that when the sample material is sufficiently small, the method for producing the sample chip as shown in FIG. 6 cannot be used. The present invention has been made in view of such problems, and an object of the present invention is to provide a sample preparation method capable of manufacturing a sample chip even when the sample material is sufficiently small.

(1) In the first aspect of the present invention, an adhesive is applied on a substrate, a spacer is arranged on the substrate so as to sandwich a sample piece from both sides, and the sample is bonded to the spacer. A transparent protective film is applied on top of the laminate to form a laminate. After the adhesive is cured, the laminate is cut out with a cutter, and the cut sample piece is attached to a glass plate, and the laminate has a predetermined thickness. A sample is prepared by polishing so as to become.
(2) The invention according to claim 2 is characterized in that the thickness of the sample piece is about 100 μm.

(1) According to the first aspect of the present invention, even a small sample chip that cannot be set on the ion slicer can be set on the ion slicer.
(2) According to the invention described in claim 2, it is possible to perform suitable ion beam etching by attaching to an ion slicer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of the sample cutting method of the present invention. The same components as those in FIG. 6 are denoted by the same reference numerals. First, the circle 1 will be described. A member constituting the sample is prepared. In the circle 1, 30 is a substrate, and 40 is a sample. The sample 40 is extremely small as shown in the figure. 31 and 32 are spacers arranged so as to sandwich the sample 40 from both sides. Since the substrate 30 and the spacers 31 and 32 are easy to process, for example, a silicon (Si) wafer is used.

  Reference numeral 34 denotes an adhesive (Glue) applied on the substrate 30. As the adhesive 34, for example, a thermosetting epoxy resin is used. The sample 40 is placed on the adhesive 34 and adhered. In addition, the spacers 31 and 32 are bonded so that the sample 40 is sandwiched from both sides. Next, as shown in circle 2, a transparent protective film 33 is applied onto the spacers 31 and 32 by applying an adhesive (thermosetting epoxy resin). Here, for example, glass is used as the protective film.

  After the adhesive has hardened, as shown in circle 3, the diamond cutter blade 21 is used to cut out the sheet to a width of 2.5 mm and a thickness of several mm. Circles 4 and 5 show a state in which the sample portion is cut out. The cut out sample portion is as shown by a circle 6. The cross-sectional view at this time is as shown in FIG. An adhesive layer 36 and spacers 31 and 32 are disposed on the substrate 30, and a sample piece 40 a is sandwiched between the spacers. The adhesive layer 35 is interposed between the sample piece 40 a and the spacers 31 and 32. A glass plate 33 is arranged. It can be seen that the sample piece 40a is small.

  Next, the cut sample portion is attached to a glass plate and polished to a thickness of 100 μm. Here, the cut sample portion is attached to the glass plate in order to facilitate polishing. Polishing can be achieved using conventional techniques. By setting the thickness of the sample portion to 100 μm, ion beam etching suitable for an ion slicer can be performed. Here, polishing is performed from both sides of the sample portion. After polishing, when the glass plate is removed, the sample chip 1 as shown by the circle 7 is manufactured. As shown in FIG. 2, since there are spacers 31 and 32 held from both sides of the sample 40 piece 40a, it appears to be large, and the prepared sample chip is set in the IS holder of the ion slicer shown in FIG. Can do. As a result, ion beam etching is performed as shown in FIG.

Thus, according to the present invention, even a small sample chip that cannot be set on the ion slicer can be set on the ion slicer.
In the above-described embodiment, the case where glass is used as a protective film for protecting the spacer is taken as an example. However, the present invention is not limited to this, and other members such as plastic can be used as long as they are transparent.

It is explanatory drawing of the sample cutting-out method of this invention. FIG. It is composition explanatory drawing of an ion slicer. It is an enlarged view of the etching part by an ion beam. It is explanatory drawing of the milling process of a sample chip | tip. It is explanatory drawing of the basic sample cutting-out method of an ion slicer. It is a figure which shows the example of a dimension of a sample chip | tip.

Explanation of symbols

1 Sample Chip 21 Diamond Cutter Blade 30 Substrate 31 Spacer 32 Spacer 33 Glass Plate 34 Adhesive 40 Sample 40a Sample Piece

Claims (2)

Apply adhesive on the substrate,
Place and adhere a spacer on the substrate so that the sample piece is sandwiched from both sides,
Applying an adhesive on the bonded sample and spacer and pasting a transparent protective film to form a laminate,
Cut out the laminate with a cutter after curing the adhesive,
A cut sample piece is attached to a glass plate, and the laminate is polished to a predetermined thickness to prepare a sample.
A method for preparing a sample.   The sample preparation method according to claim 1, wherein the thickness of the sample piece is about 100 μm.

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