JP2007108042A - Sample analysis method and sample processing apparatus - Google Patents

Abstract

An SEM sample and a STEM sample are produced without performing a sample surface flattening operation using a FIBAD film, which has been performed prior to cross-section processing and thin piece processing by FIB, and without causing FIB irradiation damage to the sample surface.
[Solution] Instead of a focused ion beam assisted deposition (FIBAD) film formed on the sample surface during sample processing, a thin thin film plate different from the target sample is transferred and fixed to the processing position for protection. A membrane.
[Selection] Figure 9

Description

  The present invention relates to sample processing using a focused ion beam. For example, the present invention relates to a sample processing method, a sample processing apparatus, and a sample analysis method for processing a sample for cross-sectional observation with a scanning electron microscope or a sample for a (scanning) transmission electron microscope with a focused ion beam.

  The miniaturization of semiconductor devices and magnetic devices has progressed year by year, and scanning electron microscopes (hereinafter abbreviated as SEM) and transmission electron microscopes (hereinafter abbreviated as TEM) A scanning transmission electron microscope (hereinafter abbreviated as STEM. TEM and STEM are representatively abbreviated as STEM below) is indispensable. In particular, for SEM observation and STEM observation of a specific cross section of a sample, high-precision cross-section forming technology and thin piece sample processing technology are essential. In order to realize this, processing by a focused ion beam (hereinafter abbreviated as FIB) is frequently used.

  Processing for specimen cross-sectional SEM observation using FIB is performed as follows. First, an FIB assisted deposition film (hereinafter abbreviated as FIBAD film) is formed in a region including a cross-sectional processing position. This FIBAD film sprays an organic gas onto the sample surface including the FIB processed portion and irradiates the film forming region with FIB, whereby the organic gas is decomposed and a gas component such as a metal is formed as a film. The reason for forming the FIBAD film is as follows. When a material having irregularities on the surface is processed by FIB, a striped artificial structure unrelated to the original sample structure is formed reflecting the irregularities on the surface. Also, the periphery of the main processing area is slightly shaved at the hem of the FIB by the low current beam (also called the hem) on the outer periphery of the FIB, and the intersection of the cross section and the plane is not vertical. Information is missing. When such a cross section is observed by STEM or SEM, a shape different from the original shape is observed. In order to avoid such a problem, a FIBAD film is formed for the purpose of flattening the sample surface. The TEM sample processing method using FIB is described in Japanese Patent No. 3547143, “Sample Processing Method”.

Japanese Patent No. 3547143 Japanese Patent Application Laid-Open No. 5-28950

  In the current sample processing method for cross-sectional SEM and STEM observation using the FIB described above, damage due to FIB on the outermost surface of the sample during sample processing has become apparent.

  Whether the cross-section to be observed by SEM or the thin sample to be TEM-observed, if the FIBAD film is formed for the purpose of flattening the surface of the mother sample and protecting the surface of the mother sample, the outermost surface of the sample is exposed by FIB irradiation. Strictly, it is slightly sputtered off, damaged, or ion-implanted, and strictly speaking, the mother sample surface does not preserve the original structure. For this reason, the reliability with respect to the analysis of the structure and composition of the outermost surface of the mother sample is lowered. Since FIB irradiation damage during FIBAD film fabrication is inevitable, it has become apparent that it is difficult to process SEM samples and STEM samples for observing a cross section without damaging the outermost surface. Even if the cross-section is made without the FIBAD film on the surface, the FIB itself is damaged by searching for the location to be processed by the FIB, or the beam is caused by the tail of the FIB itself (low current beam expansion). The periphery slightly wider than the scanning region is damaged, and even if the vertical cross section is intended to be processed, the intersection of the surface and the cross section is processed to have a roundness rather than a right angle.

  As a method for forming such a film on the processing surface without using the FIBAD film, there is a method of forming a vapor deposition film before forming the FIBAD film. In this case, (i) the time loss is large because the sample must be processed by a vapor deposition apparatus which is a separate apparatus. (B) It is not easy to form a deposited film only in a specific micron region to be observed. In particular, it is extremely difficult to apply a deposited film only to a specific micron region in a large-diameter wafer. (C) If the object has deep irregularities, the deposited film will not be uniformly filled up to the bottom of the deep depressions, so if the cross section is processed with FIB, a striped artificial structure is formed in the cross section as described above, etc. There are problems.

In other words, there were the following problems.
(1) To provide a sample processing method for easily forming a surface protective film without performing a sample surface flattening operation using a FIBAD film, which has been performed prior to cross-section processing and thin piece processing by FIB,
(2) Providing a sample processing method with little time loss and the observation outermost surface of the sample is not damaged by FIB irradiation,
(3) To provide an evaluation method capable of correctly evaluating the outermost surface and the subsurface structure of a sample obtained using FIB.

  In the present invention, preferably, a thin plate is used instead of the FIBAD film that has been conventionally formed on the sample surface during FIB sample processing. A thin plate different from the target sample is moved to the processing position to form a protective film.

  The thin plate is prepared in advance in the vicinity of the sample in the sample chamber, and the thin plate is transferred by fine movement means provided in the sample chamber of the sample processing apparatus. The sample directly under the thin plate thus transferred is simultaneously subjected to FIB processing to produce a sample for SEM observation or a sample for STEM observation.

  Preferably, a thin plate prepared in advance in the vacuum sample chamber is transferred to the sample surface, a focused ion beam is irradiated onto the thin plate, the sample is processed together with the thin plate, a thin sample is prepared, and the thin sample is extracted from the sample. And a step of removing the thin plate from the thin piece sample, and a step of analyzing the surface of the thin piece sample with a charged particle beam. Here, analysis means observation, measurement, and analysis.

  If there are minute foreign matter or minute protrusions on the sample surface, a thin plate is installed to cover them. In that case, it is preferable that the thin plate has a concave shape with a small thickness, and the concave shape of the thin plate is a groove shape, a rectangular surface shape, or a substantially spherical surface. It is convenient to form a mark on the extended line of the processing position of the sample, and to transfer the mark previously formed on the thin plate to the surface of the sample in accordance with the mark formed on the sample.

  Preferably, a sample stage for moving the sample in the vacuum sample chamber, a focused ion beam irradiation optical system for irradiating the focused ion beam, and secondary particles generated from the sample by irradiation of the focused ion beam , A display unit for displaying a sample image using a signal from the detector, a gas supply unit for supplying a source gas of a deposition film formed on the irradiated portion of the focused ion beam, and a vacuum sample A thin plate transporting means for transporting a thin plate inside the chamber and transferring it to the surface of the sample, and the thin plate has a mark made of a positioning opening, a protrusion or a notch on the peripheral edge. It is. The marks are preferably provided at four intersections between two orthogonal straight lines that intersect at the approximate center of the thin plate and the thin plate end, or at a location near the thin plate end on the two straight lines.

  According to the present invention, the sample surface can be easily protected. For example, the FIBAD film formation that has been performed prior to the sample processing for cross-sectional observation by FIB and TEM sample processing is not performed, and FIB irradiation damage is not applied to the outermost surface of the sample. High resolution evaluation is possible.

  Embodiments of the present invention will be described below with reference to the drawings.

[Example 1]
First, a configuration example of a sample processing apparatus that realizes the sample processing method of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a configuration example of a sample processing apparatus according to the present invention. The sample processing apparatus 21 detects secondary particles such as secondary electrons and secondary ions generated from the FIB irradiation optical system 25 that irradiates the FIB 24 to the mother sample 23 placed on the sample stage 22 and the irradiation part of the FIB 24. The detector 26 includes gas supply means 27 for supplying a gas necessary for forming the FIBAD film in the FIB irradiation region. The gas supply means 27 has a nozzle 28 whose diameter is about 50 μm in the gas irradiation section, and can supply gas only to the FIB irradiation section. The thin thin plate 30 to be transferred to the surface of the mother sample 23 is installed in a thin film holder 31, and this thin film holder 31 is installed in a wafer holder 32 that directly installs a wafer that is the mother sample 23. Move to the field of view and cut out the thin plate 30 of a required size from the large thin film member with the FIB 24 or prepare the thin plate 30 of a predetermined size, and use the probe 33 to process the processing region of the mother sample 23 Can be transported. The probe 33 can be moved in the sample chamber 35 by the probe fine movement mechanism 34 in at least three axes (vertical direction, direction orthogonal to the direction parallel to the FIB scanning direction). The micro sample fixture 36 is a member for fixing a micro sample extracted from the mother sample 23. The micro sample fixture 36 can be mounted on the micro sample fixture holder 37 and tilted as necessary. A specific configuration of the wafer holder 32 will be described later with reference to FIG.

  The surface and processed cross section of the mother sample 23 can be observed by the SEM optical system 39 and the SEM image can be displayed on the display means 40. Control of each part is performed by the SEM control device 41, the probe control device 42, the FIB control device 43, the gas supply control device 44, the secondary electron detection control device 45, and the stage control device 46 connected to the central control device 47. The central control device 47 has a function of giving a command such as moving each mechanism system, and a function of accumulating data from each unit to perform calculation and storage. The configuration of the apparatus is not limited to that shown in FIG. 1, and the optical axis of the focused ion beam irradiation optical system may always be inclined with respect to the sample moving stage surface.

  Next, a wafer holder 32 on which a thin film holder or the like is mounted will be described with reference to FIG. The mother sample 23 used here is a silicon wafer having a diameter of 300 mm, and is placed on a wafer holder 32 that can be attached to and detached from the sample stage 22 that is movable in the sample chamber 35. In addition to the mother sample 23, the wafer holder 32 includes a micro sample fixture holder 37 for installing a micro sample fixture 36, and a thin film holder 31 for holding a transfer thin film or a thin film member 30 capable of excising the thin film. Installed. The micro sample fixture holder 37 is mounted on a holder deck 38. In this embodiment, five are mounted, and the holder deck 38 can be tilted by a directly connected small motor or tilting mechanism 39, and a minute sample can be tilted substantially. With this structure, the processed surface of the extracted micro sample can be observed by FIB or SEM, and the processed surface can be further freely processed.

  One or a plurality of micro sample fixtures 36 can be mounted on the micro sample fixture holder 37, and a plurality of micro samples can be fixed to each micro sample fixture 36. A small sample can be mounted. As specific numerical values, five micro samples are fixed to each micro sample fixture 36, and five micro sample fixture holders 37 on which the micro sample fixtures 36 are mounted are installed on the holder deck 38. In addition, 25 minute samples can be extracted and processed by one loading of the holder deck. The thin film member 30 is fixed to a thin film member holder 31 that is detachably installed on the wafer holder 32. The protective thin film can be excised from the thin film member 30 as necessary using a probe and transferred to a desired position of the mother sample 23.

  A specific example of the thin film member 30 is shown in FIG. FIG. 3 (a) shows an example in which a plurality of types of micro thin plate members are mounted, and the transfer thin film portions 51a, 51b, 51c, 51d to be transferred are provided in advance so as to be easily separated. And an opening portion 52 and a cutout portion 53 that becomes a cutting edge by FIB. The specific dimensions of the thin film member 30 are 4 mm in length, 5 mm in width, and about 1 μm in thickness, and a reinforcing rim (not shown) is disposed at an appropriate position on the back surface of the thin film member 30 in order to prevent bending. The material may be a metal such as copper or platinum, or silicon, and is manufactured using a semiconductor process or the like. If the width of the opening 52 is set to about 1 to 2 μm and the cutout portion 53 is set to about 1 to 2 μm, the excision time by FIB is several tens of seconds, and the probe is fixed to the corner of the transfer thin film unit 51 before excision. By doing so, the minute thin plate can be separated in about 1 minute. The thin film member is configured so that a large number of small thin plates for transfer can be mounted, and FIG. 3 (a) is merely an example.

  FIG. 3B shows a state where the transfer thin film portions 51 a and 51 b are extracted from the thin film member 30. For example, the transfer thin film portion 51a will be described. First, one end 56 of the transfer thin film portion 51a is excised with FIB, and then the probe 54a is brought into contact with the vicinity of the end portion of the transfer thin film portion 51a, and the tip portion and the transfer thin film portion 51a are contacted. Are connected by the FIBAD film 55a. Next, the FIB is irradiated to the position 57 corresponding to the desired length of the fine thin plate and cut. In the case of the transfer thin film part 51a, since the width is 3 μm, the cutting by FIB irradiation is completed in about 1 minute. Thereby, the transfer thin film portion 51a can be completely separated from the thin film member 30, and the transfer thin film portion 51a can be transported to a desired place by the movement by the probe 54a. Similarly, the transfer thin film portion 51b can be transported by the above-described procedure, and can be moved to a desired position of the sample. FIG. 1 shows an example of the configuration of the sample processing apparatus according to the present invention, including the case where the focused ion beam irradiation optical system is perpendicular to the sample moving stage.

  Here, known examples similar to the present invention will be shown to clarify differences from the present invention. Japanese Patent Application Laid-Open No. 5-28950 (Patent Document 2) discloses a method of processing a cross section for observation using a movable mask in a vacuum. This will be described with reference to FIG. The purpose of Patent Document 2 is to improve the processing position accuracy of cross-section processing, to form a cross-section at a desired position of a fine device, and to observe the structure of the cross-section. In order to realize this, in Patent Document 2, in the processing method of forming a desired cross section in the sample 502 by the FIB 501, first, the square hole 503 is processed by the FIB 501 having a large current (FIG. 5A), and then the vacuum. A movable mask 504 that is movable inside and has a cleaved surface of the crystal as an end face is placed close to a desired cross section by a manipulator 505 (FIG. 5B), and the linear of the movable mask 504 is formed by a fine FIB 501 ′. Finishing is performed by scanning along the end face (FIG. 18C). It is assumed that a clear cross-section 506 is obtained by such a method (FIG. 18D).

  On the other hand, the present invention differs from Patent Document 2 in the following points. (1) In the present invention, the thin plate is moved to the sample surface, and then the cross section is processed by FIB. At that time, the end face of the thin plate (movable mask in Patent Document 2) is not used, and the mother plate is used together with the thin plate. Samples are also FIB processed at the same time. That is, the present invention is completely different from Patent Document 2 in that the thin plate and the sample under the thin plate are processed at the same time, and the thin plate according to the present invention does not necessarily have a linear end surface and does not need to have a rectangular shape. (2) The thin film of the present invention is not always connected to the probe for conveyance, but is connected to the probe when necessary, and is disconnected when it becomes unnecessary or fixed on the surface of the mother sample. (3) The thin plate in the present invention is not used only at the time of cross-section finishing by FIB, but is used from the first roughing. In this respect, the present invention is fundamentally different from Patent Document 2.

[Example 2]
As a typical embodiment of the sample processing method according to the present invention, the procedure of the sample processing method will be described below with reference to FIG.
(i) As shown in FIG. 4A, first, a thin plate to be transferred is processed in advance. This may be created in the same environment immediately before creating the TEM sample, or the member 81 created by another method may be brought into the sample chamber. Here, an example is shown in which FIB is created near the sample. The size of the thin plate to be transferred is 2 × 10 μm and the thickness is 0.5 μm. First, the FIB 82 is scanned with respect to the member 81 having a thickness of 200 × 200 μm and a thickness of 0.5 μm to form a groove 83 having a “U” shape. By opening, a cantilever 84 having a width of 2 μm and a length of 10 μm is created. The material of the member 81 used here is silicon. Of course, the size and material are not limited to this example.

(ii) Next, as shown in FIG. 4B, the target position of the sample 85 that is the mother sample to be observed is included and supported by a single support portion 86 as in the conventional microsampling method. A wedge-shaped micro sample 87 is prepared by drilling with FIB 88, 88 '. The specific size was made of FIBs 88 and 88 'that were incident on the mother sample 85 from the vertical and inclined directions so that the width was about 4 μm, the length was about 15 μm, and the depth (the height of the sample) was about 15 μm.

(iii) Next, as shown in FIG. 4 (c), the probe 89 is brought into contact with the tip of the cantilever beam 84 created earlier so that the tip of the probe 89 is fixed to the tip of the cantilever 84. Then, the FIBAD film 90 is formed. After fixing the probe 89, the other end 91 of the cantilever 84 is irradiated with FIB to cut out the rectangular fine thin plate 92.

(iv) As shown in FIG. 4 (d), the fine rectangular thin plate 92 to be transferred can be separated by the above operation and transferred to the target position by the movement of the probe 89.

(v) As shown in FIG. 4E, the thin plate 92 is brought into contact by moving the probe 89 to the surface of the wedge-shaped micro sample 87 prepared previously. At this time, the FIBAD film 93 is formed on a part of the thin plate 92 and the sample surface, and the thin plate 92 and the micro sample 87 are integrated.

(vi) Next, as shown in FIG. 4 (f), the support portion 86 supporting the micro sample 87 is irradiated with FIB to cut the support portion 86, and the micro sample 94 is a sample 85 which is a mother sample. Separate and extract from

(vii) As shown in FIG. 4G, the extracted micro sample 87 is transported to and brought into contact with the upper surface of the micro sample fixture 95 by moving the probe 89 and the sample stage. After the contact, the micro sample 94 and the micro sample fixture 95 are fixed by the FIBAD films 96 and 96 '. Thereafter, the tip of the probe 89 is irradiated with FIB to completely separate the micro sample 87 and the probe 89 from each other. By these operations, the micro sample 87 can stand on the micro sample fixture 95.

(viii) Finally, as shown in FIG. 4 (h), together with the transferred thin plate 92, both sides are removed by FIB with reference to the pre-laid mark to form the observation thin film portion 97, thereby completing the STEM sample. .

  The method for transferring the thin plate is not limited to the above method, and may be the method shown in FIG. FIG. 5A shows a thin plate assembly 210 having a plurality of thin plates 211 to be transferred. Each thin plate 211 is supported only by a support portion 212, and a space 213 is formed between the thin plates 211. The thin plate assembly 210 is fixed in advance to the tip of the movable probe 214. If necessary, the probe 214 is moved to a desired position of the sample 215 and brought into contact with or in proximity to the support 212 to be cut by the FIB. As a result, the thin plate 211 is separated from the thin plate set 210 and transferred to the sample 215 as a thin plate 211 a that plays a role of protecting the sample surface. Reference numeral 212 ′ in FIG. 5B indicates a cut portion by FIB. )

  FIG. 5C shows another example in which a plurality of thin plates can be used. In this example, a relatively large thin plate substrate 216 is fixed to the tip of the probe 214. If necessary, the probe 214 is moved to a desired position of the sample 215 and brought into contact with or brought close to the thin plate of a desired size. It is a technique to cut by. FIG. 5D shows a state in which the thin plate 211b having a desired size is separated from the thin plate substrate by the FIB cutting unit denoted by reference numeral 217, and the cut and separated thin plate 211b is installed at a desired position. By such a method and means, a thin plate having a desired shape and a desired shape can be transferred to a desired position on the sample.

  FIG. 6 is a diagram for explaining a method of processing the periphery of the target portion of the sample using the above-described thin plate transfer method.

  FIG. 6A is a plan view of a sample 220 in which plugs 221 are integrated in a lattice point shape, showing a plane at a certain depth in a semiconductor device. A state in which a mark 223 for specifying a position is applied to a defective plug 222 of interest by a known technique is shown.

  In FIG. 6B, the thin plate 224 held at the tip of the probe support portion 228 is moved above the target portion. Since the thin plate is provided with a plurality of marks 225, the position of the thin plate 224 is adjusted so that the mark 225 coincides with the mark 223 on the sample. By doing in this way, an attention part will be right under the intersection of two perpendicular lines which pass through a mark of a thin board. A thin plate is adhered to the sample surface so that the positional relationship of the marks is not broken.

  FIG. 6C shows a state in which the concave holes 226 are processed by FIB on both sides, leaving marks on the thin plate 224. By irradiating obliquely with respect to at least one of the two concave holes 226, the two concave holes 226 intersect at a deep portion of the target portion. In order to irradiate in such an oblique direction, the sample stage may be inclined, and in the case of this example, the sample may be inclined with the axis passing through the two marks 225 as the inclination axis and grooved in the deep part of the hole.

  Further, in FIG. 6D, a micro sample including the target portion can be separated from the original sample 220 by opening a hole 227 perpendicular to the sample surface so as to overlap both the concave holes 226.

  Thus, since a thin plate is installed on the sample surface instead of the conventional FIBAD film, the original shape of the sample can be observed without any FIB irradiation damage. However, the sample surface is subjected to FIB irradiation for a short time until the thin plate 224 from FIG. 6A to FIG. 6B is installed. In this case, if an optical microscope or a scanning electron microscope is attached to the apparatus, the target position may be covered by roughly moving with such a microscope. When this method cannot be taken, it is preferable to follow the method of the third embodiment described below.

Example 3
FIG. 7 shows another thin plate fixing method according to an embodiment of the present invention. Here, a description will be given of a method when it is not desired to irradiate the sample surface with FIB, particularly when an observation place is specified.

(i) As shown in FIG. 7A, the sample surface is irradiated with FIB, and a specific observation place 231 is searched from the structure and markings of the sample surface. At this time, the specific observation place 231 is prevented from entering the FIB irradiation region 232 (observation visual field). This is because a specific structure or marking coordinates that are more than the FIB irradiation dimension away from the observation location 231 are examined with an optical microscope, SEM, CAD information, etc., and the observation area to be noticed is moved by moving the stage on the field of view. Can be located outside.

(ii) Next, as shown in FIG. 7B, the FIB irradiation region 232 is moved by moving the probe 234 to which the fine thin plate 235 is fixed in consideration of the coordinate of the observation place and the coordinate difference (offset) between the specific structure. Is brought into contact with the sample surface so as to enclose the observation place 231 outside. After the contact, the FIBAD film 236 is formed on a part of the fine thin plate 235 in the FIB irradiation region 232 and the sample surface, and the thin plate 235 and the sample are integrated. Thereafter, the tip of the probe 234 is irradiated with FIB to completely separate the fine thin plate 235 and the probe 234.

(iii) Next, as shown in FIG. 7C, the observation place 231 is moved into the FIB irradiation region 232 by moving the sample stage and the probe 234 at the same speed. Alternatively, the FIB irradiation region 232 is image-shifted so that the observation place 231 enters the FIB irradiation region 232, and then the FIBAD film 236 is formed so as to fix the micro thin plate 235, and the probe 234 and the micro thin plate 235 are moved. It may be separated. By such a fixing method of the fine thin plate, the fine thin plate 235 can be fixed without the observation place 231 being damaged by the FIB irradiation. Thereafter, the cross section of the observation location 231 may be taken out by FIB irradiation, and observation may be performed by SEM or FIB, or the observation location 231 may be extracted as a fine sample piece and then sliced and subjected to TEM or STEM observation. .

Example 4
In the present embodiment, another method of fixing the thin plate 235 different from the third embodiment will be described with reference to FIG.
(i) As shown in FIG. 8A, the coordinates of a specific observation location 231 are examined using an optical microscope, SEM, CAD information, or the like. Since the coordinates examined by these methods are a system that can be linked to the FIB stage, the FIB is offset by adding a distance larger than the visual field size to the designated coordinates in advance so that the observation place 231 does not enter the FIB irradiation area 232. Move the stage.

(ii) Next, as shown in FIG. 8B, the probe 234 to which the fine thin plate 235 is fixed is moved to the FIB irradiation region (field of view) 232. At this stage, the probe 234 is not brought into contact with the sample.

(iii) Next, as shown in FIG. 8C, the FIB stage is moved to the coordinates examined in advance so that the observation place 231 enters the FIB irradiation region 232. Next, the probe 234 is brought into contact with the sample surface while irradiating FIB and viewing the secondary electron image. At this time, the FIB may be in a blanking state. After stopping the stage movement, the probe is gradually lowered, and the probe is stopped after contact. Here, the FIBAD film 236 is formed on a part of the thin plate 235 and the surface of the sample 232, and the thin plate 235 is fixed to the sample. Next, the tip of the probe 234 is irradiated with FIB to separate the thin thin plate 235 and the probe 234. Thereby, the thin thin plate 235 can be fixed without the observation place 231 receiving FIB irradiation damage. Thereafter, the cross-section of the observation location 231 may be taken out by FIB irradiation and observation may be performed by SEM or FIB. Alternatively, the observation location 231 may be extracted as a fine sample piece and then thinned and subjected to TEM or STEM observation.

Example 5
Of the thin plate fixing method according to the present invention, an embodiment further different from the above embodiment will be described with reference to FIG. The apparatus used in this embodiment has a configuration in which the FIB optical axis is arranged in a positional relationship perpendicular to the sample surface at the reference position.

  First, the sample surface far from the target location is put into the field of view, the observation magnification of the FIB is set to a low magnification, and the fine thin plate 235 connected to the probe 234 as shown in FIG. Move. At this time, the fine non-irradiated area of FIB can be widened by separating the thin thin plate 235 from the sample surface by, for example, 100 to 300 μm. In this state, the FIB is put into a blanking state. Reference numeral 232L denotes the FIB irradiation range at a low magnification.

  Next, the coordinates of the observed observation point 231 are input, and the sample stage is moved. In order to emphasize the point of interest 231 of the sample, a mark is given by another means. This mark was formed by scanning each segment on two orthogonal straight lines having the target portion as an intersection with a low-power laser, for example. In FIG. 9A, the mark is not visible because it is covered with a thin thin plate.

  Ideally, the point of interest of the sample corresponding to the input coordinates moves to the center of the screen, but the stage movement includes some errors, so it is not exactly at the center but near the center. Since the thin plate is separated from the sample surface in advance, a rectangular region of several tens to several hundreds of μm on the sample surface becomes a shadow of the thin plate, and even if the stage error amount is taken into consideration, Be sure to enter the shadow of the thin plate 235. That is, there is no direct irradiation of the sample surface by the ion beam. This method may be used for the purpose of blocking the electron beam with respect to a sample which is easily damaged by electron beam irradiation instead of the ion beam.

  After stopping the sample stage, the blanking state of the beam is released, and the observation magnification is increased while the probe 234 is gradually lowered (approaching the sample surface). When the mark 238 previously set as shown in FIG. 9B comes out of the fine thin plate 235 in the observation screen 232H at a high magnification, the fine thin plate mark 237 and the sample mark 238 coincide with each other. As described above, the fine thin plate 235 is brought into contact with the sample surface while finely adjusting the position of the stage or the probe 234. As shown in FIG. 9B, when the mark 238 on the sample surface and the mark 237 on the micro thin plate coincide with each other, the attention point is the intersection of two straight lines including the mark.

  When the micro thin plate 235 comes into contact with the sample, the probe 234 is stopped to move, a small size FIBAD is attached to the thin plate and the sample surface, the thin plate is fixed, and the connection between the probe 234 and the micro thin plate 235 is connected to the FIB. Cut by irradiation. Through such a series of operations, the region of interest 231 can be moved to the approximate center of the thin plate 235 without irradiating the target portion of the sample with an ion beam or an electron beam.

  FIG. 10 is a flowchart showing the above work procedure. First, in step S010, the observation magnification of FIB is set to a low magnification or a minimum. Next, in step S020, the FIB is blanked so that the sample is not irradiated with the FIB. In other words, the SIM image is not seen. In this state, coordinates stored in advance as observation coordinates are input, and the sample stage is moved so that the target position moves to the center of the screen (step S030). In the next step S040, the probe is moved so that the center of the thin plate at the tip of the probe comes to the center of the screen. The probe moving mechanism connected to the probe can be moved so that the probe is moved to the retracted position, or when called, the center of the screen, that is, the center of the thin plate is on the FIB optical axis. Further, the thin plate called on the FIB optical axis is stored and moved so as to be located in a state separated by about 100 μm from the sample surface. Accordingly, the thin plate can cover a wide area with a low magnification without being damaged.

  In step S050, by releasing the FIB blanking state, a SIM image in which the thin plate surface is at the center of the screen and the sample surface is visible around the thin plate surface is displayed on the screen. Next, in step S060, the FIB observation magnification is gradually increased and at the same time the probe is lowered (step S070), and there is a thin plate at the center of the screen, and the magnification is adjusted while adjusting so that the sample surface can be seen around it. If the attention is paid to the sample surface around the thin plate while gradually adjusting the increase in magnification and the lowering of the thin plate, a mark drawn in advance near the target position can be confirmed (step S080). If the mark on the sample surface can be confirmed, the increase in observation magnification and the descent of the thin plate are stopped (step S090). Next, in step S100, the stage is finely adjusted in parallel with the sample surface so that the mark on the sample surface coincides with the mark provided on the thin plate. If the two marks match, the point of interest is located at the intersection of two straight lines passing through the thin plate mark, that is, directly below the center of the thin plate.

  Next, in step S110, the probe is lowered at a very low speed and brought into contact with the sample surface, and at the same time as the contact confirmation (step S120), the probe descent is stopped (step S130). Here, as step S140, the thin plate is fixed to the sample surface with about two FIBAD films. After fixing the thin plate, cutting by FIB irradiation is performed at a location near the thin plate of the probe (step S150). As a result, the thin plate can cover the target location so that it is located at the center of the thin plate, and in the process up to fixing, the target location is not subjected to FIB irradiation and there is almost no damage to the surface of the target location. I can say that. Finally, in step S160, the probe is retracted.

  After this, the sample is FIB processed together with the thin plate so as to leave the target location (the center of the thin plate) to form an STEM sample. This step may be performed by the method described above.

Example 6
This example is a sample processing method and an observation method for transferring a thin plate to a sample surface and observing the shape of the sample surface with SEM or STEM. The shape of the sample surface is flat, has regular irregularities, has irregular irregularities, or has minute deposits or minute formations on the surface.

  FIG. 11 is a schematic cross-sectional view showing an example in which a thin plate is bonded to a sample surface having an uneven surface. FIG. 11A shows an example in which the surface of the sample 237 is flat, or there are regular irregularities but the surface is flat. In this case, a thin plate 235a having a smooth contact surface 238 may be used. The thin plate 235a can be manufactured by FIB as described in FIGS. FIG. 11B shows an example in which the surface of the sample 237 has regular irregularities such as dry etching. In this case, the contact surface 238 may have a shape matching the uneven shape on the surface of the sample 237. By using the thin plate 235b in which the shape of the contact surface 238 is matched to the uneven shape of the surface of the sample 237, processing fringes generated in the cross section during the cross section processing of the sample 237 by FIB can be minimized, and misunderstanding of the interpretation of the cross section I won't be born.

  In the case where the observation object is a minute foreign matter 239c adhering to the surface of the sample 237 as shown in FIG. 11C or a minute protrusion 239d generated on the surface of the sample 237 as shown in FIG. When an object is damaged or disappears, a concave thin plate 235c having a recess in the thickness direction as shown in FIG. 11C is used. The manufacturing method of the concave thin plate 235c will be described in the next embodiment. The important point is to cover the observation objects 239c and 239d with the concave portions 240c and 240d of the concave thin plates 235c and 235d so as not to directly contact the observation objects 239c and 239d. By using such concave thin plates 235c and 235d, the minute foreign matter 239c and the minute protrusion 239d are not deformed by the adhesive force of the thin plates 235c and 235d, and spattering by FIB irradiation does not occur. In addition, when the minute foreign matter 239c and the minute protrusion 239d are smaller than the thickness of the thinned sample, the sample processing is performed while maintaining the original shape without directly irradiating the minute foreign matter 239c and the minute protrusion 239d with FIB during sample preparation. Thus, the entire minute foreign matter 239c and the entire minute protrusion 239d can be observed by STEM.

  In addition, the cross section of the dent part provided in the thin plate 235c is not limited to a rectangle like the dent part 240c, and it is sufficient that the dent part has a recess so as not to directly contact the object, and the dent shown in FIG. An arc shape may be used like the part 240d.

  Next, the in-plane shape of the thin plate will be described. The minute thin plate is not limited to the rectangular shape described so far, and for example, various shapes as shown in FIG. 12 can be applied. Here, a feature common to the thin plate shown in FIG. 12 is that a mark is provided in order to accurately set the center of the thin plate at the target portion on the sample.

  In the thin plate shown in FIG. 12A, a triangular notch mark 246a is arranged at the center of the four sides of the thin plate 245a. Of these four cutout marks 246a, the intersection of two straight lines connecting the vertices of the cutout marks facing each other is the center of the thin plate 245a. When the thin plate 245a is moved so that the marks on the sample coincide with the extended lines of the two straight lines connecting the vertices of the notches facing each other, the target location on the sample is directly below the center of the thin plate.

  The thin plate shown in FIG. 12B has a shape having a triangular protrusion mark 246b at the center of the four sides of the thin plate 245b. This thin plate has an effect that the small mark on the sample can be accurately aligned as compared with the thin plate shown in FIG.

  FIG. 12 (c) shows a thin plate 245c provided with a T-shaped through mark 246c near the center inside of the four sides, and FIG. 12 (d) shows an L-shaped through mark 246d arranged near the center inside of the four sides. A thin plate 245d is shown. The centers of the two straight lines that connect the centers of the two T-shapes or L-shapes facing each other are the centers of the thin plates 245c and 245d.

  These marks 246a, 246b, 246c, and 246d are also characterized in that since the marks have unique shapes, the sample surface or thin film is imaged, and only the marks are recognized from the images, so that they can be easily specified. By adopting easy-to-recognize marks, the work of placing the center of the thin plate at the target location on the sample is performed so that the mark on the thin plate is recognized and the mark on the sample is positioned on two straight lines connecting the opposing marks. By controlling the probe, it is possible to perform unattended operation instead of the operator of the apparatus. For example, by performing probe control, stage control, and nozzle control from the central controller 47, the work flow as described in FIG. 10 can be automatically performed. In order to accurately recognize a mark on a thin plate, it is important to make it an artificial and geometric shape that is difficult to appear on a sample, and a shape that makes it easy to uniquely determine a straight line connecting two marks. .

Example 7
Here, a method of manufacturing a concave thin plate that does not directly contact an observation target as shown in FIG. 11 will be described. This thin plate can be produced by the following three methods: (1) electroforming (electroforming) method, (2) semiconductor manufacturing process method, and (3) microsampling method. These will be described in order.

  A method for producing a concave thin plate by electroforming will be described with reference to FIG. First, as shown in FIG. 13A, a photosensitive resist 252 is applied on the metal substrate 251. The resist thickness is equal to or slightly thicker than the thickness of the finished concave thin plate. For example, it is about 0.5 μm. Next, as shown in FIG. 13B, a mask 253 that shields the desired shape is brought into close contact with the resist 252 and exposed. As a result, as shown in FIG. 13C, the exposed resist 252B is cured, and the unexposed resist 252A directly under the mask 253 is not altered. Next, when developed, as shown in FIG. 13 (d), the resist 252B that has been modified by exposure is not changed by development, and the resist 252A having a desired shape that has not been exposed is removed, and the opening 254 is formed. It is formed.

  Next, as shown in FIG. 13 (e), the metal substrate 251 is immersed in an electrolyte solution (not shown) in this state, and a voltage is applied between the metal substrate 251 and the electrode immersed in the metal solution electrolyte. Then, a thin metal plate 255 of the electrolyte component is deposited (plated) in the opening 254 from which the resist has been removed. The metal substrate 251 is taken out of the electrolytic solution, and as shown in FIG. 13 (f), the resist 256 is applied again over the resist 252B and a part of the metal thin plate 255, and FIGS. 13 (a) to 13 (d) are applied. Through the same process, an opening 257 having the size of the concave portion of the thin metal plate 255 is provided.

  Next, as shown in FIG. 13G, by performing dry etching or reactive ion etching on the opening 257 provided in the metal thin film 255, a rectangular recess 258 as shown in FIG. Then, it is wet-etched by immersing it in an acid to form an arc-shaped recess as shown in FIG. Finally, by immersing the metal substrate 251 in the resist removing solution, a minute thin plate 255 having a target recess 258 as shown in FIG.

  Depending on the semiconductor manufacturing process, a concave thin plate can be similarly produced. In the above-described method shown in FIG. 13E, a CVD process of a semiconductor process is applied instead of the plating process, and dry etching is performed in the process of FIG. Can be produced. The dimensional accuracy can be improved more accurately than the electroforming method.

  A method for manufacturing a concave thin plate by the microsampling method will be described with reference to FIG. For example, consider a process of creating a concave flake using a silicon plate as a raw material.

  As shown in FIG. 14A, deep concave holes 273a and 273b are provided by FIB 272 on both sides of a region 271 where it is assumed that a concave thin piece will be formed on the sample substrate 270. The figures are shown from a perspective other than the FIB for clarity. Since the width of the region 271, that is, the distance between the deep concave holes 273 a and 273 b is the thickness of the finished thin plate, the distance between the deep concave holes is, for example, about 1 μm. As shown in FIG. 14B, after processing the groove 274 by FIB so that the thickness is about half at the center of the region 271, the sample 270 is tilted (the sample tilt is in a state for easy understanding). Is not written). Cuts 275a, 275b, and 275c are processed around the region 271 so that the region 271 is supported only by the support portion 276. Here, as shown in FIG. 14C, the probe 277 is introduced into the field of view, is brought close to the side surface of the notch 275a, and is connected by the FIBAD film 278. Then, the region 271 is separated from the sample 270 by cutting the support portion 276 with the FIB 272. By raising the probe 277 as shown in FIG. 14D, the target region 271 is extracted as a thin plate 271A.

  Next, as shown in FIG. 14E, the extracted thin plate 271A is transported to another place of the sample 270 and brought close to the sample surface. In this state, the deposition film 278 connecting the probe 277 and the thin plate 271A, the tip of the probe 277, or a part of the thin plate 271A is removed by the FIB 272. At this time, the probe 277 and the thin plate 271A are separated while operating the probe 277 so that the groove 274 faces the surface of the sample 270. FIG. 14 (f) shows a state where the groove 274 of the thin plate 271 is separated so as to face the sample surface. At this time, since the thin plate 271 and the groove 274 are oriented in an arbitrary direction, the direction is corrected by rotating the sample stage in consideration of the introduction direction of the probe support portion, the form of the STEM observation sample to be created, and the orientation. The important point is that since the probe introduction direction does not change greatly each time the work is performed, the created probe tip shape is related to the next work and sample. In addition, the direction of the thin plate and the direction of the groove are determined and connected to the probe support portion. In this example, the direction of the groove 274 is set to the vertical direction on the screen from the relationship with the observation sample. As shown in FIG. 14G, after the rotation of the sample stage is corrected, the probe support 261 that connects the thin plate 271A to the tip is introduced into the field of view and brought into contact with the thin plate 271A. The FIBAD film 279 is formed of the FIB 272 so that the tip of the probe support 261 and the thin plate 271A are connected. In this way, a probe having a thin plate 271A having a recess at the tip of the probe support portion 261 can be produced. In FIG. 14H, the probe is brought into contact with the sample surface with reference to the mark 281 on the inspection sample 280. Reference numeral 282 denotes an upper surface of a plug for making electrical contact with the internal structure of the device formed on the semiconductor wafer. The defective part of the plug is located at the intersection of the two marks 281.

  Since the thin plate 271A described above has a recess on the lower surface, it does not directly contact the upper surface of the plug. Conventionally, in order to observe the cross section of such a sample, the FIBAD film was formed on the plug of interest and the cross section processing or thin piece processing was performed. Therefore, when the FIBAD film was formed, excessive charge was injected into the plug by FIB irradiation. Originally, the thin film of the atomic layer order on the bottom surface of the plug, which is the target of TEM observation at high magnification, was damaged, and the original defect morphology could not be observed. On the other hand, in this method, the upper surface of the plug is covered in a non-contact manner and is not directly irradiated with FIB, so that no charge is injected into the plug of interest and the sample surface is directly irradiated with FIB. Therefore, the original defect form can be preserved, and observation at a high magnification becomes possible.

Example 8
This example relates to a sample processing method and an observation method for transferring a thin plate to a sample surface and observing the shape of the sample surface with an SEM.

  FIG. 15 shows a sample processing method. As shown in FIG. 15A, the thin plate 292 is first prepared, adhered to the probe 289, and the probe 289 is moved to ground the thin plate 292 to the surface of the sample 285. At this time, a FIBAD film 293 is formed on a part of the thin plate 292 and the sample surface, and the thin plate 292 is fixed to the sample 285. Thereafter, the probe 289 and the thin plate 292 are once separated by sputtering using FIB. In FIG. 15B, FIB 297 is irradiated around the fixed thin plate 292, and groove processing is performed so as to separate from the sample 285 leaving the support portion 286. In FIG. 15C, the probe 289 and the micro sample 294 are connected again by the FIBAD film 290, and the support 286 supporting the micro sample 294 is irradiated with FIB and cut, so that the micro sample 294 is the mother sample. Separate from sample 285. Thereafter, the micro sample 294 can be extracted from the sample 285 by raising the probe 289.

  Next, as shown in FIG. 15D, the extracted micro sample 294 is transported to and brought into contact with the upper surface of the micro sample fixture 295 by moving the probe 289 and a sample stage (not shown). After the contact, the micro sample 294 and the micro sample fixture 295 are fixed by the FIBAD films 296, 296 '. The micro sample 294 and the probe 289 are separated by irradiating the tip of the probe 289 with FIB. As shown in FIG. 15 (e), the micro sample 294 extracted and transferred by these operations can stand on the micro sample fixture 295. Next, the FIBAD film 293 fixing the thin plate 292 is sputtered away with the FIB 297 so that the thin plate 292 can be easily separated from the micro sample 294. Next, by raising the probe 289 as shown in FIG. 15 (f), the thin plate 292 can be removed from the micro sample 294, and the surface of the micro sample 294, that is, the surface of the sample 285 is exposed. The original surface of the sample can be observed. Furthermore, it is possible to observe a cross section directly under the surface without any surface damage. In particular, the sample piece in such a form has an advantage that the surface shape can be observed from a low angle of several degrees with respect to the surface, so that the cross section and the uneven state of the surface can be observed in detail.

  Such a sample processing method and sample observation method are effective for evaluating the surface morphology of a resist for argon fluoride or a low dielectric constant film in a semiconductor device that is easily deformed by electron beam irradiation without damage. .

  15E and 15F, after fixing the micro sample 294 to the micro sample fixture 295, the probe 289 is separated from the thin plate 292 by FIB irradiation, the FIBAD film 293 is removed, and the probe 283 is made to be a thin plate. The thin plate 292 may be separated from the micro sample 294 by pushing the thin plate 292 by moving while contacting the 292. In FIG. 15 (e), if the thinning process is performed, an STEM sample is obtained, and the inside of the sample can be observed, so that high-magnification observation in the vicinity of the sample surface without damage peculiar to the present method becomes possible. In this case, the sample may be observed without removing the thin plate.

  Furthermore, even when the sample surface is very sensitive to an electron beam or an ion beam and the surface of the sample that is easily damaged by these beam irradiations is not observed, it is not necessary to remove it as in this embodiment. The method according to the present invention can be applied, and once the surface is covered with a thin plate, the orientation is easy to observe with SEM, etc., and the focus adjustment is performed, and then the thin plate is removed immediately before screen shooting to minimize beam damage. The surface can be observed while being suppressed to the limit.

Example 9
Example 8 is an etching hole evaluation method in which the sample processing method according to the present invention is applied to the evaluation of the hole shape immediately after etching of a contact hole in a semiconductor process. FIG. 16 explains the problems of the conventional sample processing method and the sample obtained thereby, and FIG. 17 explains the effect of the sample obtained by the method of the present invention.

  Conventionally, when the contact hole shape immediately after etching is observed with high resolution, the sample is cleaved so that the diameter of the contact hole passes, and the cross section is observed with high resolution SEM, or the inside of the hole is filled with a deposition film and thinned. STEM observation. Cross-sectional exposure by cleavage and SEM observation method are simple, but the reliability is low in terms of whether the cleavage plane has passed through the diameter of the fine hole accurately, and many measurements were required for reliable data acquisition. . In addition, STEM observation of the cross section can be measured much more accurately than SEM observation of the cleaved surface, but filling the hole with the FIBAD film causes the following problems and does not always give good results.

  FIG. 16A schematically shows an STEM sample for observing the contact hole shape with high resolution, and the row of contact holes 301 is exposed in a half-section state on the thin sample 300. In the figure, reference numeral 330 denotes an electron beam incident direction (STEM observation direction). Conventionally, when preparing such a thin sample, it is usual to fill the sample surface and the contact hole with the FIBAD film 302 in order to avoid sagging of the sample cross section due to FIB irradiation. FIG. 16B shows a cross-sectional transmission image obtained by STEM observation of the sample processed in this way. A contact hole 301 is formed in the sample substrate 303, and a FIBAD film 302 is formed in the sample surface and in the contact hole 301.

  However, when high-resolution observation is performed, an opening portion of a hole that is originally vertical is in a round state 304 by FIB irradiation. Further, an amorphous layer 305 that should not originally exist is formed on the sample surface and the contact hole surface, and the original surface of the sample is not preserved. In particular, the bottom surface of the contact hole is formed so as not to cause damage in the etching process, and the damaged region 306 is formed on the bottom surface of the hole by sample preparation, although the evaluation has attracted attention. . Furthermore, when the aspect ratio of the contact hole (ratio of the depth to the hole diameter) is increased, the FIBAD film is not completely filled in the hole, and the cavity 307 is formed. A vertical stripe 308 is formed under 307. Such cavities 307 and vertical stripes 308 are not generated in the etching process, but are artificial structures generated in the sample manufacturing process, which hinder the original sample evaluation. In particular, the vertical stripes 308 on the bottom of the hole interfere with the important shape evaluation of the bottom of the hole. Therefore, a sample processing method that causes such alteration and generation of artificial structures at the sample preparation stage must be excluded.

  On the other hand, FIG. 17 (a) shows a contact hole array obtained by using the sample processing installation shown in FIG. 1 and using the thinning step of FIG. 4 and the thin plate removing step of FIG. It is an external view of the thin piece sample 311 produced so that it may include. The thin sample 310 has a shape in which the contact hole 312 row is stored in the silicon base 311, and there is no conventional FIBAD film on the sample surface 313. FIG. 16B is the transmission image of FIG. 16A, and the contact hole 312 in the sample can be observed with good contrast. Moreover, there is no round shape of the hole opening 314 which is a problem in the conventional method, and the vertical shape is maintained. In addition, the sample surface 313 and the hole bottom surface 315 have no damaged region (amorphous layer) due to FIB irradiation, and the original shape of the contact hole can be observed. Furthermore, even if a very small amount of elemental analysis is performed on this sample, the original composition analysis of the sample is not hindered by the composition signal of the FIBAD film, and reliable data can be obtained even for the very small amount analysis. .

  FIG. 16C is a transmission image obtained by inclining the thin piece sample 310, and the shape and diameter of the opening 314 part and the bottom part 315 of the contact hole 312 can be accurately measured. The hole diameter can be measured much more accurately than the method of exposing the cross section as shown in FIGS.

The basic block diagram of the sample processing apparatus which is one Example of this invention. The figure explaining the installation means of the thin plate assembly which is one Example of this invention. The figure explaining the example of the thin plate assembly by this invention. The figure explaining the procedure of STEM sample preparation by this invention. The figure explaining the fixing method of the fine thin plate which is one Example of this invention. The figure explaining the implementation procedure of the sample preparation by this invention. The figure explaining the fixing procedure of the fine thin plate which is one Example of this invention. The figure explaining another fixing method of the fine thin plate which is one Example of this invention. The figure explaining another fixing method of the fine thin plate which is one Example of this invention. The flowchart which shows the procedure of the method of FIG. The figure explaining the cross-sectional shape of a micro thin board. The figure explaining the planar shape and mark shape of a micro thin plate. The figure explaining the preparation procedure of a micro thin board. The figure explaining another preparation procedure of a micro thin board. The figure explaining the sample preparation procedure by this invention. The figure explaining the problem which arises by the conventional sample processing method. The figure explaining the sample obtained with the sample processing method by this invention. The figure explaining the difference with a similar well-known example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Sample processing apparatus, 23 ... Sample, 25 ... FIB irradiation optical system, 30 ... Thin plate, 31 ... Thin plate holder, 32 ... Wafer holder, 47 ... Observation cross section, 51a, 51b, 51c, 51d ... Transfer thin film part, 54a, 54b ... probe, 210 ... thin plate assembly, 211a, 211b ... separated thin plate, 216 ... thin plate, 225 ... mark, 239c ... fine foreign matter, 239d ... small projection, 274 ... groove, 292 ... thin plate

Claims (10)

A sample analysis method for analyzing a sample surface with a charged particle beam,
Transferring a thin plate prepared in advance in the vacuum sample chamber to the sample surface;
Irradiating the thin plate with a focused ion beam to process the sample together with the thin plate to produce a thin piece sample;
Extracting the flake sample from the sample;
Removing the thin plate from the thin sample;
And a step of analyzing the surface of the thin sample with the charged particle beam.   2. The sample analysis method according to claim 1, wherein the thin plate is installed so as to cover minute foreign matters or minute protrusions on the sample surface.   3. The sample analysis method according to claim 2, wherein the thin plate has a concave shape in which a part of the thin plate is thin.   4. The sample analysis method according to claim 3, wherein the concave shape of the thin plate is a groove shape, a rectangular surface shape, or a substantially spherical surface.   2. The sample analysis method according to claim 1, wherein a mark is formed on an extension line of a processing position of the sample, and a mark previously formed on the thin plate is transferred to the sample surface according to the mark formed on the sample. A sample analysis method characterized by:   2. The sample analysis method according to claim 1, wherein in the step of transferring the thin plate to the surface of the sample, the gas assisted deposition film by the focused ion beam irradiation or the focused ion beam irradiation to the sample is generated at the end of the thin plate. A sample processing method comprising forming a film of the sputtered particles and fixing the thin plate to the sample surface.   2. The sample analysis method according to claim 1, wherein the thin plate is provided at a point of intersection of two orthogonal straight lines intersecting at an approximate center of the thin plate and the thin plate end portion, or at a location close to the thin plate end portion on the two straight lines. A sample analysis method comprising an opening, a projection, or a notch to be a marked mark.   2. The sample analysis method according to claim 1, wherein the thin plate is manufactured using a semiconductor process or an electroforming process. A sample stage in which a sample is placed and moved in a vacuum sample chamber;
A focused ion beam irradiation optical system for irradiating a focused ion beam;
A detector for detecting secondary particles generated from the sample by irradiation of the focused ion beam;
Image display means for displaying a sample image using a signal from the detector;
A gas supply means for supplying a raw material gas for the deposition film formed in the irradiated portion of the focused ion beam;
A thin plate transporting means for transporting a thin plate inside the vacuum sample chamber and transferring it to the surface of the sample;
The thin plate has a mark formed of a positioning opening, a protrusion, or a notch at a peripheral edge thereof.   10. The sample processing apparatus according to claim 9, wherein the mark is provided at a point of intersection of two orthogonal straight lines intersecting at a substantially center of the thin plate and the thin plate end portion, or at a location near the thin plate end portion on the two straight lines. The sample processing apparatus characterized by the above-mentioned.

Images