JP6925608B2 - Cross-section processing observation method, cross-section processing observation device - Google Patents

Cross-section processing observation method, cross-section processing observation device Download PDF

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JP6925608B2
JP6925608B2 JP2017053714A JP2017053714A JP6925608B2 JP 6925608 B2 JP6925608 B2 JP 6925608B2 JP 2017053714 A JP2017053714 A JP 2017053714A JP 2017053714 A JP2017053714 A JP 2017053714A JP 6925608 B2 JP6925608 B2 JP 6925608B2
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JP2017183280A (en
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欣 満
欣 満
敦 上本
敦 上本
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Hitachi High Tech Science Corp
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02Details
    • H01J37/22Optical or photographic arrangements associated with the tube
    • H01J37/224Luminescent screens or photographic plates for imaging ; Apparatus specially adapted therefor, e.g. cameras, TV-cameras, photographic equipment, exposure control; Optical subsystems specially adapted therefor, e.g. microscopes for observing image on luminescent screen
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00Sampling; Preparing specimens for investigation
    • G01N1/28Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/22Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
    • G01N23/225Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/30Electron-beam or ion-beam tubes for localised treatment of objects
    • H01J37/317Electron-beam or ion-beam tubes for localised treatment of objects for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation

Description

本発明は、集束イオンビームによって形成した試料の特定観察対象物を含む特定部位に向けて電子ビームを照射して断面像を取得し、特定観察対象物の3次元立体像を構築する断面加工観察方法、断面加工観察装置に関するものである。 In the present invention, a cross-sectional processing observation is performed to obtain a cross-sectional image by irradiating a specific site including a specific observation object of a sample formed by a focused ion beam with an electron beam to obtain a three-dimensional stereoscopic image of the specific observation object. It relates to a method and a cross-section processing observation device.

例えば、半導体デバイス等の試料の内部構造を解析したり、立体的な観察を行ったりする手法の1つとして、集束イオンビーム(Focused Ion Beam;FIB)鏡筒と電子ビーム(Electron Beam;EB)鏡筒を搭載した複合荷電粒子ビーム装置を用いて、FIBによる断面形成加工と、その断面をEB走査による走査型電子顕微鏡(Scanning Electron Mi
croscope;SEM)観察を繰り返して、対象試料の断面像を複数枚取得した後、これら複数の断面像を重ね合わせて試料の3次元立体像を構築する断面加工観察方法が知られている(例えば、特許文献1)。
For example, as one of the methods for analyzing the internal structure of a sample such as a semiconductor device or performing three-dimensional observation, a focused ion beam (FIB) lens barrel and an electron beam (EB) are used. Using a composite charged particle beam device equipped with a lens barrel, cross-section forming by FIB and scanning electron microscope (Scanning Electron Mi) by EB scanning the cross section
A cross-sectional processing observation method is known in which a plurality of cross-sectional images of a target sample are obtained by repeating croscope (SEM) observation, and then the plurality of cross-sectional images are superposed to construct a three-dimensional stereoscopic image of the sample (for example). , Patent Document 1).

この断面加工観察方法は、FIBによる断面形成加工をCutと称し、EBによる断面観察をSeeと称して、CutとSeeを繰り返して3次元画像を構築する一連の手法がCut&Seeとして知られている。この手法では、構築した3次元立体像から、対象試料の立体的な形体を様々な方向から見ることができる。更に、対象試料の任意の断面像を再現することができるという、他の方法にはない利点を有している。 In this cross-section processing observation method, cross-section formation processing by FIB is referred to as Cut, cross-section observation by EB is referred to as See, and a series of methods for constructing a three-dimensional image by repeating Cut and See is known as Cut & See. In this method, the three-dimensional shape of the target sample can be seen from various directions from the constructed three-dimensional image. Furthermore, it has an advantage that other methods do not have, that is, it is possible to reproduce an arbitrary cross-sectional image of the target sample.

具体的な一例として、試料に対してFIBを照射してエッチング加工を行い、試料の断
面を露出させる。続いて、露出させた断面をSEM観察して断面像を取得する。続いて、
再度エッチング加工を行って、次の断面を露出させた後、SEM観察により2枚目の断面
像を取得する。このように、試料の任意の方向に沿ってエッチング加工とSEM観察とを
繰り返して、複数枚の断面像を取得する。そして、最後に、取得した複数枚の断面像を重
ね合わせることによって、試料の内部を透過させた3次元立体像を構築する方法が知られている。
As a specific example, the sample is irradiated with FIB and etched to expose the cross section of the sample. Subsequently, the exposed cross section is observed by SEM to obtain a cross-sectional image. continue,
After etching again to expose the next cross section, a second cross-sectional image is obtained by SEM observation. In this way, etching processing and SEM observation are repeated along an arbitrary direction of the sample to obtain a plurality of cross-sectional images. Finally, there is known a method of constructing a three-dimensional stereoscopic image in which the inside of the sample is transmitted by superimposing a plurality of acquired cross-sectional images.

特開2008−270073号公報Japanese Unexamined Patent Publication No. 2008-2700073

しかしながら、例えば、観察対象の試料が細胞などの生体試料である場合、パラフィンなどの包埋剤によって包埋して包埋ブロックに固定されている。こうした生体試料を加工観察対象にして、対象試料中に分散する微小な細胞などの特定観察対象物だけを選択的に高分解能の3次元立体像を構築する場合、包埋ブロックをFIBやEBによって観察すると、包埋ブロックの表層だけの観察となり、対象試料(包埋ブロック)中に分散する細胞などの特定観察対象物の存在位置を特定することができない。このため、特定観察対象物が点在する試料に対して上述したCut&See手法を適用すると、FIBによる加工領域を試料全体に設定し、試料全体を対象にCutとSeeを繰り返し行い、特定観察対象物を加工断面内に出現させる必要があり、観察に膨大な時間を要するという課題があった。 However, for example, when the sample to be observed is a biological sample such as a cell, it is embedded with an embedding agent such as paraffin and fixed to the embedding block. When such a biological sample is used as a processing observation target and a high-resolution three-dimensional stereoscopic image is selectively constructed only on a specific observation target such as minute cells dispersed in the target sample, the embedding block is formed by FIB or EB. When observing, only the surface layer of the embedding block is observed, and the existence position of a specific observation object such as cells dispersed in the target sample (embedding block) cannot be specified. Therefore, when the above-mentioned Cut & See method is applied to a sample in which specific observation objects are scattered, a processing region by FIB is set for the entire sample, and Cut and See are repeatedly performed for the entire sample to perform the specific observation object. It is necessary to make the sample appear in the processed cross section, and there is a problem that it takes an enormous amount of time for observation.

また、こうした試料全体を対象にCutとSeeを繰り返し行うと、生成される断面画像も膨大な数になる。このため、特定観察対象物の3次元立体像を生成するには、こうした多量の断面像の中から、特定観察対象物を含む部位の断面像だけを抽出して3次元立体像を構築するという、非効率で時間のかかる手順が必要になるという課題もある。特に、生体試料の場合、その多くは特定観察対象物のサイズが微小であり、これを高精度な3次元立体像にするためには、FIBによる加工間隔をできる限り狭くして、広い視野でのSEM観察を繰り返す必要がある。そのため、試料全体で大量の断面像を取得することになるが、特定観察対象物を含む特定部位以外の断面像は不要であり、こうした不要な断面像を処理したり一時保存するために画像処理装置に過剰な負荷がかかるという課題もある。 Further, when Cut and See are repeatedly performed on the entire sample, the number of cross-sectional images generated becomes enormous. Therefore, in order to generate a three-dimensional stereoscopic image of a specific observation object, only a cross-sectional image of a part including the specific observation object is extracted from such a large number of cross-sectional images to construct a three-dimensional stereoscopic image. There is also the problem that inefficient and time-consuming procedures are required. In particular, in the case of biological samples, the size of the specific observation object is very small in most cases, and in order to obtain a highly accurate three-dimensional image, the processing interval by the FIB is made as narrow as possible to widen the field of view. It is necessary to repeat the SEM observation of. Therefore, a large amount of cross-sectional images are acquired for the entire sample, but a cross-sectional image other than a specific part including a specific observation object is unnecessary, and image processing is performed to process or temporarily store such an unnecessary cross-sectional image. There is also the problem that the device is overloaded.

更に、特定観察対象物が試料に含まれていない場合は、長時間を要して行った試料全体のCutとSeeによる観察が全て無駄になってしまうという、効率的に観察を行う際の障害もあった。 Furthermore, if the specific observation object is not included in the sample, all the observations by Cut and See of the entire sample, which took a long time, are wasted, which is an obstacle in efficient observation. There was also.

本発明は、前述した事情に鑑みてなされたものであって、試料に含まれる特定観察対象物を含む特定部位だけを迅速に、かつ効率的に観察を可能にして、特定観察対象物の3次元立体像を容易にできる断面加工観察方法および断面加工観察装置を提供することを目的とする。 The present invention has been made in view of the above-mentioned circumstances, and enables quick and efficient observation of only a specific part including a specific observation object contained in a sample, so that the specific observation object 3 It is an object of the present invention to provide a cross-section processing observation method and a cross-section processing observation device capable of easily forming a three-dimensional stereoscopic image.

上記課題を解決するために、本発明のいくつかの態様は、次のような断面加工観察方法、断面加工観察装置を提供した。
すなわち、本発明の断面加工観察方法は、観察対象の試料全体を光学顕微鏡で観察して、前記試料に含まれる特定観察対象物の前記試料内におけるおおよその3次元位置座標情報を取得する位置情報取得工程と、前記3次元位置座標情報に基づいて、前記試料のうち前記特定観察対象物が存在する特定部位に向けて集束イオンビームを照射して、該特定部位の断面を露出させる断面加工工程と、前記断面に電子ビームを照射して、前記特定観察対象物を含む所定の大きさの領域の画像を取得する断面像取得工程と、前記断面加工工程および前記断面像取得工程を所定間隔で所定方向に沿って複数回繰返し行い、取得した複数の前記画像から前記特定観察対象物を含む3次元立体像を構築する立体像生成工程と、を有することを特徴とする。
In order to solve the above problems, some aspects of the present invention provide the following cross-section processing observation method and cross-section processing observation device.
In other words, cross-section processing and observation method of the present invention is to observe the entire sample to be observed with an optical microscope, to obtain an approximate three-dimensional position coordinate information within said sample of a particular observation object contained in the sample position Based on the information acquisition process and the three-dimensional position coordinate information, cross-sectional processing that irradiates a focused ion beam toward a specific part of the sample in which the specific observation object exists to expose the cross section of the specific part. The step, the cross-sectional image acquisition step of irradiating the cross section with an electron beam to acquire an image of a region of a predetermined size including the specific observation object, and the cross-sectional processing step and the cross-sectional image acquisition step are performed at predetermined intervals. in repeated a plurality of times along a predetermined direction, and having a three-dimensional image generating step of constructing a three-dimensional image including the specific observation object from a plurality of pre-outs image obtained, the.

本発明の断面加工観察方法は、観察対象の試料を予め光学顕微鏡筒で観察して、特定観察対象物が存在するXYZ方向の位置座標情報を取得し保存する。光学顕微鏡筒によるZ(深さ)方向の位置座標は、光学顕微鏡筒として共焦点実体顕微鏡を用いて、XY位置座標を固定して焦点位置を変えながら観察することによって得られる。 In the cross-sectional processing observation method of the present invention, the sample to be observed is observed in advance with an optical microscope tube, and the position coordinate information in the XYZ direction in which the specific observation object is present is acquired and stored. The position coordinates in the Z (depth) direction by the optical microscope tube are obtained by observing while changing the focal position by fixing the XY position coordinates using a confocal stereomicroscope as the optical microscope tube.

こうして得られた特定観察対象物の3次元座標情報に基づいて、観察対象の試料をFIBによって断面露出加工を行なう。この時、特定観察対象物が存在しない領域は、FIBによって加工間隔を広げて短時間で加工し、断面像も特に取得することはない。そして、位置座標情報によって特定観察対象物を含む特定部位に到達したら、予め定めた狭い間隔で試料を加工し、加工した断面のうち特定観察対象物を含む領域のSEM断面像を取得する。 Based on the three-dimensional coordinate information of the specific observation object thus obtained, the sample to be observed is subjected to cross-section exposure processing by FIB. At this time, the region where the specific observation object does not exist is processed in a short time by widening the processing interval by the FIB, and the cross-sectional image is not particularly acquired. Then, when the specific portion including the specific observation object is reached by the position coordinate information, the sample is processed at a predetermined narrow interval, and the SEM cross-sectional image of the region including the specific observation object in the processed cross section is acquired.

そして、FIBの加工位置とSEM画像をセットで保存する。特定観察対象物を含んだ特定部位の画像データの取得が完了したら、断面像の取得と狭い間隔のFIB加工を終了し、次の特定部位に接近するまで広い間隔で短時間にFIB加工する。こうして全ての特定部位の断面像の取得ができたら加工を終了する。または、加工間隔を一定として対象物がない領域は断面像を取得せず、対象物がある領域で断面像を取得する。これにより、所望の情報を効率よく取得することができる。 Then, the processing position of the FIB and the SEM image are saved as a set. When the acquisition of the image data of the specific part including the specific observation object is completed, the acquisition of the cross-sectional image and the FIB processing at a narrow interval are completed, and the FIB processing is performed at a wide interval in a short time until the next specific part is approached. When the cross-sectional images of all the specific parts can be obtained in this way, the processing is completed. Alternatively, the cross-sectional image is not acquired in the region where the processing interval is constant and there is no object, but the cross-sectional image is acquired in the region where the object is present. Thereby, desired information can be efficiently acquired.

このように、本発明の断面加工観察方法によれば、光学顕微鏡筒による光学的な観察で特定観察対象物の存在する座標位置を把握しておくことによって、迅速に、かつ効率的に特定観察対象物を含む特定部位の観察を行い、特定観察対象物の3次元立体像を容易に得ることを可能にする。 As described above, according to the cross-sectional processing observation method of the present invention, by grasping the coordinate position where the specific observation object exists by optical observation with the optical microscope tube, the specific observation can be performed quickly and efficiently. By observing a specific part including an object, it is possible to easily obtain a three-dimensional stereoscopic image of the specific observation object.

本発明では、前記特定観察対象物は複数種類設定され、それぞれの特定観察対象物ごとに前記断面加工工程を行うことを特徴とする。
また、本発明では、前記光学顕微鏡として、共焦点実体顕微鏡を用いることを特徴とする。
The present invention is characterized in that a plurality of types of the specific observation object are set, and the cross-section processing step is performed for each specific observation object.
Further, the present invention is characterized in that a confocal stereomicroscope is used as the optical microscope.

また、本発明では、前記断面像取得工程において、前記断面のエネルギー分散型X線検出により前記特定観察対象物を含む前記特定部位の断面組成像を更に取得し、前記立体像生成工程において、取得した複数の前記断面組成像から前記特定観察対象物を含む3次元立体組成像を構築することを特徴とする。 Further, in the present invention, in the cross-sectional image acquisition step, a cross-sectional composition image of the specific portion including the specific observation object is further acquired by energy-dispersed X-ray detection of the cross section, and is acquired in the stereoscopic image generation step. It is characterized in that a three-dimensional three-dimensional composition image including the specific observation object is constructed from the plurality of cross-sectional composition images.

本発明の断面加工観察装置は、特定観察対象物を含む試料を載置する試料台と、前記試料に集束イオンビームを照射する集束イオンビーム鏡筒と、前記試料に電子ビームを照射する電子ビーム鏡筒と、前記試料を光学的に観察する光学顕微鏡筒と、前記試料から発生する二次電子を検出する二次電子検出器又は反射電子を検出する反射電子検出器と、前記光学顕微鏡筒によって前記試料内における前記特定観察対象物の存在位置を特定して、前記試料のうち前記特定観察対象物が存在する特定部位に向けて前記集束イオンビーム鏡筒から集束イオンビームを照射して断面を露出させ、前記断面に前記電子ビーム鏡筒から電子ビームを照射して前記特定観察対象物を含む所定の大きさの領域の画像を取得させ、前記画像から前記特定観察対象物を含む特定部位の3次元立体像を構築する制御部と、を備えたことを特徴とする。 The cross-sectional processing observation apparatus of the present invention includes a sample table on which a sample containing a specific observation object is placed, a focused ion beam lens barrel that irradiates the sample with a focused ion beam, and an electron beam that irradiates the sample with an electron beam. By the lens barrel, an optical microscope barrel for optically observing the sample, a secondary electron detector for detecting secondary electrons generated from the sample, a reflected electron detector for detecting reflected electrons, and the optical microscope barrel. The position of the specific observation object in the sample is specified, and the focused ion beam is irradiated from the focused ion beam barrel toward the specific part of the sample in which the specific observation object is present to obtain a cross section. It is exposed, and the cross section is irradiated with an electron beam from the electron beam lens barrel to acquire an image of a region of a predetermined size including the specific observation object, and the image of the specific portion including the specific observation object is obtained. It is characterized by having a control unit for constructing a three-dimensional stereoscopic image.

本発明の断面加工観察装置によれば、試料内で特定観察対象物を含む特定部位のおおよその位置座標を光学顕微鏡筒によって予め把握できるため、集束イオンビーム鏡筒による試料の加工時に、特定部位に迅速に接近して、特定部位以外の領域は粗く、特定部位は細かく集束イオンビーム筒で加工を行うことができる。これにより、特定観察対象物を含む特定部位の高分解能の断面像を、短時間で迅速に得ることができる。 According to the cross-sectional processing observation device of the present invention, the approximate position coordinates of the specific part including the specific observation object in the sample can be grasped in advance by the optical microscope tube, so that the specific part is processed when the sample is processed by the focused ion beam lens barrel. The region other than the specific region is rough, and the specific region can be finely processed with a focused ion beam tube. As a result, a high-resolution cross-sectional image of a specific part including a specific observation object can be quickly obtained in a short time.

また、本発明の断面加工観察装置によれば、集束イオンビーム鏡筒によって形成された試料断面のうち、特定観察対象物を含む特定部位だけに、電子ビーム鏡筒から電子ビームを照射して断面像のデータを取得するため、試料全域に渡って断面像を得る従来の観察装置と比較して、保存する断面像のデータ容量が格段に削減され、低コストに断面加工観察装置を構成することができる。
更に、特定観察対象物を含む特定部位の電子ビームによる断面像取得の際には、高分解能で画像化することで、試料全域に渡って断面像を得る従来の観察装置と比較して、より解像度の高い3次元立体像を生成することが可能になる。
Further, according to the cross-section processing observation apparatus of the present invention, among the cross-sections of the sample formed by the focused ion beam barrel, only a specific part including the specific observation object is irradiated with an electron beam from the electron beam barrel to form a cross-section. In order to acquire image data, the data capacity of the cross-sectional image to be stored is significantly reduced compared to the conventional observation device that obtains a cross-sectional image over the entire sample, and a cross-section processing observation device can be configured at low cost. Can be done.
Furthermore, when acquiring a cross-sectional image with an electron beam of a specific part including a specific observation object, it is possible to obtain a cross-sectional image over the entire sample by imaging with high resolution, as compared with a conventional observation device. It becomes possible to generate a three-dimensional stereoscopic image with high resolution.

また、本発明では、前記試料から発生する特性X線を検出するEDS検出器を備え、前記制御部は、前記特定部位の3次元立体組成像を構築することを特徴とする。 Further, the present invention is characterized in that an EDS detector for detecting characteristic X-rays generated from the sample is provided, and the control unit constructs a three-dimensional three-dimensional composition image of the specific portion.

本発明によれば、特定観察対象物を含む特定部位の加工を短時間で高精度に行うことができ、これにより、特定観察対象物の高分解能な3次元立体像を容易に、かつ迅速に生成することが可能になる。 According to the present invention, it is possible to process a specific part including a specific observation object with high accuracy in a short time, thereby easily and quickly producing a high-resolution three-dimensional stereoscopic image of the specific observation object. It becomes possible to generate.

第一実施形態の断面加工観察装置を示す概略構成図である。It is a schematic block diagram which shows the cross-section processing observation apparatus of 1st Embodiment. 断面加工観察方法の一実施形態を段階的に示したフローチャートである。It is a flowchart which showed one Embodiment of the cross-section processing observation method step by step. 試料を光学顕微鏡筒によって観察した際の模式図である。It is a schematic diagram when observing a sample with an optical microscope tube. SEM画像の取得領域となる特定部位を示す模式図である。It is a schematic diagram which shows the specific part which becomes the acquisition area of the SEM image. 加工観察方法の変形例を示すフローチャートである。It is a flowchart which shows the modification of the processing observation method. 第二実施形態の断面加工観察装置を示す概略構成図である。It is a schematic block diagram which shows the cross-section processing observation apparatus of 2nd Embodiment. 第三実施形態の断面加工観察装置を示す概略構成図である。It is a schematic block diagram which shows the cross-section processing observation apparatus of 3rd Embodiment. 第二実施形態の断面加工観察方法に係る投影図である。It is a projection drawing which concerns on the cross-section processing observation method of 2nd Embodiment. 第三実施形態の断面加工観察方法に係る投影図である。It is a projection drawing which concerns on the cross-section processing observation method of 3rd Embodiment. 第四実施形態の断面加工観察装置を示す概略構成図である。It is a schematic block diagram which shows the cross-section processing observation apparatus of 4th Embodiment. 第四実施形態の断面加工観察方法を示す説明図である。It is explanatory drawing which shows the cross-section processing observation method of 4th Embodiment. 第四実施形態の断面加工観察方法を示す説明図である。It is explanatory drawing which shows the cross-section processing observation method of 4th Embodiment. 第四実施形態の断面加工観察方法を示す説明図である。It is explanatory drawing which shows the cross-section processing observation method of 4th Embodiment. 第四実施形態の断面加工観察方法を示す説明図である。It is explanatory drawing which shows the cross-section processing observation method of 4th Embodiment.

以下、図面を参照して、本発明の断面加工観察方法、断面加工観察装置について説明する。なお、以下に示す各実施形態は、発明の趣旨をより良く理解させるために具体的に説明するものであり、特に指定のない限り、本発明を限定するものではない。また、以下の説明で用いる図面は、本発明の特徴をわかりやすくするために、便宜上、要部となる部分を拡大して示している場合があり、各構成要素の寸法比率などが実際と同じであるとは限らない。 Hereinafter, the cross-section processing observation method and the cross-section processing observation device of the present invention will be described with reference to the drawings. It should be noted that each of the embodiments shown below is specifically described in order to better understand the gist of the invention, and is not limited to the present invention unless otherwise specified. In addition, the drawings used in the following description may be shown by enlarging the main parts for convenience in order to make the features of the present invention easy to understand, and the dimensional ratios of the respective components are the same as the actual ones. Is not always the case.

(断面加工観察装置:第一実施形態)
図1は、第一実施形態の断面加工観察装置を示す概略構成図である。
本実施形態の断面加工観察装置10は、集束イオンビーム(FIB)鏡筒11と、電子ビーム(EB)鏡筒12と、光学顕微鏡(ОМ)筒13と、ステージ(試料台)15を備えた試料室14とを、少なくとも有している。集束イオンビーム鏡筒11、電子ビーム鏡筒12、および光学顕微鏡筒(光学顕微鏡)13は、試料室14にそれぞれ固定されている。
(Cross-section processing observation device: first embodiment)
FIG. 1 is a schematic configuration diagram showing a cross-section processing observation device of the first embodiment.
The cross-section processing observation device 10 of the present embodiment includes a focused ion beam (FIB) lens barrel 11, an electron beam (EB) lens barrel 12, an optical microscope (ОМ) tube 13, and a stage (sample table) 15. It has at least a sample chamber 14. The focused ion beam barrel 11, the electron beam barrel 12, and the optical microscope barrel (optical microscope) 13 are fixed to the sample chamber 14, respectively.

集束イオンビーム鏡筒11、電子ビーム鏡筒12、および光学顕微鏡筒13は、ステージ15に載置された試料Sに向けて、集束イオンビーム(FIB)21、電子ビーム(EB)22、および可視光(VL)23をそれぞれ照射可能に配置されている。 The focused ion beam barrel 11, the electron beam barrel 12, and the optical microscope barrel 13 are directed toward the sample S placed on the stage 15, and the focused ion beam (FIB) 21, the electron beam (EB) 22, and the visible beam (EB) 22 are visible. The light (VL) 23 is arranged so that it can be irradiated.

集束イオンビーム鏡筒11から照射される集束イオンビーム21と、電子ビーム鏡筒12から照射される電子ビーム22とが試料S上でそれぞれ直交するように、集束イオンビーム鏡筒11と電子ビーム鏡筒12とを配置すると、加工された断面に対し垂直に電子ビームを照射でき、高い分解能の断面像が取得できるので、より好ましい。 Focused ion beam barrel 11 and electron beam mirror so that the focused ion beam 21 emitted from the focused ion beam barrel 11 and the electron beam 22 emitted from the electron beam barrel 12 are orthogonal to each other on the sample S. It is more preferable to arrange the cylinder 12 because the electron beam can be irradiated perpendicularly to the processed cross section and a high-resolution cross-sectional image can be obtained.

ここで、試料Sの一例としては、樹脂等で包埋された生体試料が挙げられる。こうした生体試料に含まれる(内包された)例えば細胞などを特定観察対象物(注目部分)として観察者が特に注目して観察する。試料が透明性がある生体試料である場合、金属等の一般材料とは異なり、光学顕微鏡筒(光学顕微鏡)13で生体試料の内部を観察することができるため、注目部の存在位置を確認できる。 Here, as an example of the sample S, a biological sample embedded in a resin or the like can be mentioned. The observer pays particular attention to observing, for example, cells contained (encapsulated) in such a biological sample as a specific observation object (part of interest). When the sample is a transparent biological sample, unlike general materials such as metals, the inside of the biological sample can be observed with an optical microscope tube (optical microscope) 13, so that the position of the attention portion can be confirmed. ..

光学顕微鏡筒(光学顕微鏡)13は、電子ビーム22の照射方向とほぼ同じ方向で観察できるように配置されている。なお、光学顕微鏡筒13の一部または全部は、試料室14内に収容されていてもよいし、試料室14とは別に配置された他の試料室に配置されていても良い。いずれの場合でも、電子ビームの照射方向とほぼ同じ方向で観察できるように配置することが好ましい。 The optical microscope cylinder (optical microscope) 13 is arranged so that it can be observed in substantially the same direction as the irradiation direction of the electron beam 22. A part or all of the optical microscope cylinder 13 may be housed in the sample chamber 14, or may be arranged in another sample chamber arranged separately from the sample chamber 14. In any case, it is preferable to arrange the electron beam so that it can be observed in substantially the same direction as the irradiation direction of the electron beam.

光学顕微鏡筒(光学顕微鏡)13は、例えば、光源にレーザ光源を備えた共焦点実体顕微鏡を用いることが特に好適である。共焦点実体顕微鏡は、試料Sの高さ(深さ)方向(光学顕微鏡の光軸に沿った方向)に高分解能で画像化できる。共焦点実体顕微鏡は、表面に微小な凹凸がある試料について、その凹凸を画像化することに用いられることが大半であるが、本実施形態では、試料Sの内部の構造について、深さ方向に沿って高分解能の画像を取得するために用いる。 For the optical microscope cylinder (optical microscope) 13, for example, it is particularly preferable to use a confocal stereomicroscope provided with a laser light source as the light source. The confocal stereomicroscope can image the sample S in the height (depth) direction (direction along the optical axis of the optical microscope) with high resolution. A confocal stereomicroscope is mostly used to image a sample having minute irregularities on its surface, but in the present embodiment, the internal structure of the sample S is oriented in the depth direction. It is used to acquire a high-resolution image along the line.

例えば、生体試料など透明性がある試料Sでは、レーザ光は透過し、試料S内にレーザ光を透過しない異物や組織があれば、それらが画像化できる。なお、周知のように、試料SのXY面画像情報は、X軸とY軸それぞれの方向に沿って試料S上を2次元走査する走査機構によってレーザ走査でなされ、試料の高さ(深さ)方向(Z軸)の情報は、輝度が最大の時のZ位置(試料Sの高さ情報)を取り込むことで3次元画像が取得される。 For example, in a transparent sample S such as a biological sample, the laser beam is transmitted, and if there is a foreign substance or tissue in the sample S that does not transmit the laser beam, they can be imaged. As is well known, the XY plane image information of the sample S is performed by laser scanning by a scanning mechanism that two-dimensionally scans the sample S along the respective directions of the X-axis and the Y-axis, and the height (depth) of the sample is obtained. As for the information in the direction (Z axis), a three-dimensional image is acquired by capturing the Z position (height information of the sample S) when the brightness is maximum.

但し、光学顕微鏡筒(光学顕微鏡)13によって得られた画像では、画像化された特定観察対象物の背後の構造は、その特定観察対象物が不透明であるために知ることができない。このように、レーザ光が反射した最上面の形状しか知ることができないが、特定観察対象物が存在する面内位置情報(XY座標)と深さ位置情報(Z座標)が得られるため、Cut&See操作で、特定観察対象物が試料S内の何れに存在するかの目安を立てることができる。 However, in the image obtained by the optical microscope tube (optical microscope) 13, the structure behind the imaged specific observation object cannot be known because the specific observation object is opaque. In this way, only the shape of the uppermost surface on which the laser beam is reflected can be known, but since the in-plane position information (XY coordinates) and the depth position information (Z coordinates) where the specific observation object exists can be obtained, Cut & Seee By the operation, it is possible to establish a guideline as to where the specific observation object exists in the sample S.

一方、集束イオンビーム21や電子ビーム22を用いた観察の場合、試料Sに透明性がある場合でも、試料Sの最表面の形態情報しか得られないの。よって、試料Sの内部に特定観察対象物が存在すると事前に分かっていたとしても、その存在位置(座標)を明らかにできない。また、光学顕微鏡画像とSEM画像のコントラストの違いによってSEM画像では注目部を把握しにくい場合がある。 On the other hand, in the case of observation using the focused ion beam 21 or the electron beam 22, even if the sample S is transparent, only the morphological information of the outermost surface of the sample S can be obtained. Therefore, even if it is known in advance that the specific observation object exists inside the sample S, its existence position (coordinates) cannot be clarified. Further, it may be difficult to grasp the attention portion in the SEM image due to the difference in contrast between the optical microscope image and the SEM image.

そこで、光学顕微鏡筒(光学顕微鏡)13を用いた光学顕微鏡観察によって、特定観察対象物を含む試料S内の小領域である特定部位の座標を、試料SのCut作業(断面加工工程)に先立って取得できる。そして、この特定観察対象物を含む特定部位の座標に基づいてCut作業(断面加工工程)を進めるが、露出した断面について電子ビーム21によるSEM画像の取得領域を確実にするために、断面に光学顕微鏡筒(光学顕微鏡)13と電子ビーム21で共通に認識できる特徴的な形態があれば、これを基準点として相対的位置関係から特定観察対象物の位置(座標)を特定することができる。 Therefore, by observing with an optical microscope using an optical microscope tube (optical microscope) 13, the coordinates of a specific part, which is a small region in the sample S including the specific observation object, are set prior to the Cut operation (cross-section processing step) of the sample S. Can be obtained. Then, the Cut operation (cross-section processing step) is carried out based on the coordinates of the specific part including the specific observation object, but in order to ensure the acquisition region of the SEM image by the electron beam 21 for the exposed cross-section, the cross-section is optical. If there is a characteristic form that can be commonly recognized by the microscope tube (optical microscope) 13 and the electron beam 21, the position (coordinates) of the specific observation object can be specified from the relative positional relationship using this as a reference point.

ステージ15は、ステージ制御部19によって制御され、試料Sを載置すると共に、XYZの各方向の移動、傾斜が可能であり、これによって、試料Sを任意の向きに調整することができる。 The stage 15 is controlled by the stage control unit 19, and the sample S can be placed on the stage 15 and can be moved and tilted in each direction of the XYZ, whereby the sample S can be adjusted in any direction.

断面加工観察装置10は、更に集束イオンビーム(FIB)制御部16と、電子ビーム(EB)制御部17と、光学顕微鏡(ОМ)制御部18とをそれぞれ備えている。集束イオンビーム制御部16は、集束イオンビーム鏡筒11を制御し、集束イオンビーム21を任意のタイミングで照射させる。電子ビーム制御部17は、電子ビーム鏡筒12を制御し、電子ビーム22を任意のタイミングで照射させる。 The cross-section processing observation device 10 further includes a focused ion beam (FIB) control unit 16, an electron beam (EB) control unit 17, and an optical microscope (ОМ) control unit 18, respectively. The focused ion beam control unit 16 controls the focused ion beam lens barrel 11 to irradiate the focused ion beam 21 at an arbitrary timing. The electron beam control unit 17 controls the electron beam lens barrel 12 to irradiate the electron beam 22 at an arbitrary timing.

光学顕微鏡制御部18は、光学顕微鏡筒13を制御して、光学焦点の位置を移動させつつ、移動の都度、試料Sの観察画像を取得し、記憶する。焦点位置は光学顕微鏡筒13の光軸に沿って、徐々に光学顕微鏡筒13に接近させるか、遠ざけるかの一方向に微動と停止を繰り返して、停止時に試料Sの画像を取得する。また、光学顕微鏡筒13の焦点位置を固定して、ステージ15をステージ制御部19によって上下一方向に微動させ、光学顕微鏡画像を取得しても良い。 The optical microscope control unit 18 controls the optical microscope cylinder 13 to move the position of the optical focal point, and acquires and stores the observation image of the sample S each time the optical focus is moved. The focal position is repeatedly finely moved and stopped in one direction of gradually approaching or moving away from the optical microscope cylinder 13 along the optical axis of the optical microscope cylinder 13, and an image of the sample S is acquired at the time of stopping. Alternatively, the focal position of the optical microscope cylinder 13 may be fixed, and the stage 15 may be finely moved in one vertical direction by the stage control unit 19 to acquire an optical microscope image.

断面加工観察装置10は、更に二次電子検出器20を備えている。二次電子検出器20は、集束イオンビーム21または電子ビーム22を試料Sに照射し、試料Sから発生した二次電子を検出する。 The cross-section processing observation device 10 further includes a secondary electron detector 20. The secondary electron detector 20 irradiates the sample S with the focused ion beam 21 or the electron beam 22, and detects the secondary electrons generated from the sample S.

なお、二次電子検出器20に代えて、または二次電子検出器20に加えて更に反射電子検出器(図示略)を設ける構成も好ましい。反射電子検出器は、電子ビームが試料Sで反射した反射電子を検出する。こうした反射電子によって、試料Sの断面像を取得することができる。 It is also preferable to provide a backscattered electron detector (not shown) in place of the secondary electron detector 20 or in addition to the secondary electron detector 20. The backscattered electron detector detects the backscattered electrons reflected by the electron beam on the sample S. A cross-sectional image of the sample S can be obtained by such reflected electrons.

断面加工観察装置10は、試料Sの断面の観察像を形成する像形成部24と、観察像を表示する表示部25とを備えている。像形成部24は、電子ビーム22を走査させる信号と、二次電子検出器20で検出された二次電子の信号とからSEM像を形成する。表示部25は像形成部24で得られたSEM像を表示する。表示部25は、例えばディスプレイ装置から構成されていればよい。 The cross-section processing observation device 10 includes an image forming unit 24 for forming an observation image of the cross section of the sample S, and a display unit 25 for displaying the observation image. The image forming unit 24 forms an SEM image from the signal for scanning the electron beam 22 and the signal of the secondary electrons detected by the secondary electron detector 20. The display unit 25 displays the SEM image obtained by the image forming unit 24. The display unit 25 may be composed of, for example, a display device.

断面加工観察装置10は、更に制御部26と、入力部27とを備える。オペレータは断面加工観察装置10の各種制御条件を、入力部27を介して入力する。入力部27は、入力された情報を制御部26に送信する。制御部26は、集束イオンビーム制御部16、電子ビーム制御部17、光学顕微鏡制御部18、ステージ制御部19、像形成部24などに制御信号を出力し、断面加工観察装置10全体の動作を制御する。 The cross-section processing observation device 10 further includes a control unit 26 and an input unit 27. The operator inputs various control conditions of the cross-section processing observation device 10 via the input unit 27. The input unit 27 transmits the input information to the control unit 26. The control unit 26 outputs a control signal to the focused ion beam control unit 16, the electron beam control unit 17, the optical microscope control unit 18, the stage control unit 19, the image forming unit 24, and the like, and operates the entire cross-section processing observation device 10. Control.

(断面加工観察装置:第二実施形態)
上述した第一実施形態では光学顕微鏡筒(光学顕微鏡)13の一部または全部が試料室14内にある構成について説明したが、光学顕微鏡筒(光学顕微鏡)13を試料室14の外部に設置してもよい。
図6は、本発明の第二実施形態の断面加工観察装置を示す概略構成図である。なお、第一実施形態と同様の構成には同一の番号を付し、重複する説明を省略する。断面加工観察装置30は、試料室14の外部に第二試料室34が形成され、この第二試料室34に光学顕微鏡筒(光学顕微鏡)33が配置されている。
(Cross-section processing observation device: second embodiment)
In the first embodiment described above, a configuration in which a part or all of the optical microscope tube (optical microscope) 13 is inside the sample chamber 14 has been described, but the optical microscope tube (optical microscope) 13 is installed outside the sample chamber 14. You may.
FIG. 6 is a schematic configuration diagram showing a cross-section processing observation device according to a second embodiment of the present invention. The same configuration as that of the first embodiment is assigned the same number, and duplicate description will be omitted. In the cross-sectional processing observation device 30, a second sample chamber 34 is formed outside the sample chamber 14, and an optical microscope cylinder (optical microscope) 33 is arranged in the second sample chamber 34.

光学顕微鏡筒(光学顕微鏡)33の一部または全部が設置された第二試料室34は、内部が真空または大気圧にされる。集束イオンビームや電子ビームが照射される試料室14は、内部が真空でなければならないが、光学顕微鏡筒(光学顕微鏡)33の設置環境は大気圧下でも差支えないので、第二試料室34を大気圧環境にすることで、真空となる試料室14の容積を小さくでき、真空排気の効率を高めることができる。 The inside of the second sample chamber 34 in which a part or all of the optical microscope cylinder (optical microscope) 33 is installed is evacuated or atmospheric pressure. The inside of the sample chamber 14 to which the focused ion beam or the electron beam is irradiated must be a vacuum, but since the installation environment of the optical microscope cylinder (optical microscope) 33 may be under atmospheric pressure, the second sample chamber 34 is used. By creating an atmospheric pressure environment, the volume of the sample chamber 14 that becomes a vacuum can be reduced, and the efficiency of vacuum exhaust can be improved.

試料室14と第二試料室34との間の試料Sの移動は、試料Sを載置する試料ホルダ35と共に搬送棒36によって行なう。移動に際しては、搬送棒36を試料ホルダ35に固定して気密扉(バルブ)37を開けた後、第二試料室34のステージ38から外した試料ホルダ35を搬送棒36によって試料室14に押し込み、試料室14内のステージ15上に試料ホルダ35を固定する。 The movement of the sample S between the sample chamber 14 and the second sample chamber 34 is performed by the transport rod 36 together with the sample holder 35 on which the sample S is placed. When moving, the transport rod 36 is fixed to the sample holder 35, the airtight door (valve) 37 is opened, and then the sample holder 35 removed from the stage 38 of the second sample chamber 34 is pushed into the sample chamber 14 by the transport rod 36. , The sample holder 35 is fixed on the stage 15 in the sample chamber 14.

試料室14のステージ15と、光学顕微鏡筒(光学顕微鏡)33を備えた第二試料室34のステージ38は、それぞれステージ制御部39a、39bによって制御される。ステージ15、38での座標情報は制御部26に保存され、第二試料室34のステージ38で得られた座標情報に基づいて、試料室14のステージ15を連動させることができる。なお、図6では、集束イオンビーム制御部や電子ビーム制御部などの記載を省略しているが、図1同様の構成である。 The stage 15 of the sample chamber 14 and the stage 38 of the second sample chamber 34 provided with the optical microscope cylinder (optical microscope) 33 are controlled by the stage control units 39a and 39b, respectively. The coordinate information in the stages 15 and 38 is stored in the control unit 26, and the stage 15 in the sample chamber 14 can be linked based on the coordinate information obtained in the stage 38 in the second sample chamber 34. Although the focused ion beam control unit and the electron beam control unit are omitted in FIG. 6, the configuration is the same as that in FIG.

(断面加工観察装置:第三実施形態)
上述した第二実施形態では光学顕微鏡筒(光学顕微鏡)13を試料室14とは別に設けた第二試料室34配置した構成について説明したが、光学顕微鏡筒(光学顕微鏡)13を設置する試料室を形成しなくてもよい。
図7は、本発明の第三実施形態の断面加工観察装置を示す概略構成図である。なお、第二実施形態と同様の構成には同一の番号を付し、重複する説明を省略する。断面加工観察装置40は、光学顕微鏡筒(光学顕微鏡)43が試料室14の外部に独立して配置されてるいる。そして、光学顕微鏡筒(光学顕微鏡)43で得た試料S内の特定観察対象物(注目部分)の座標を、集束イオンビーム制御部や電子ビーム制御部(図1を参照)でも読み取れるように、一部共通化された制御部46を有する。試料室14の外部に独立して光学顕微鏡筒(光学顕微鏡)43を設けることにより、例えば、それぞれを別室に設置して作業を行なうなど、機器の設置面での自由度が高められる。
(Cross-section processing observation device: third embodiment)
In the second embodiment described above, the configuration in which the second sample chamber 34 in which the optical microscope cylinder (optical microscope) 13 is provided separately from the sample chamber 14 is arranged has been described, but the sample chamber in which the optical microscope cylinder (optical microscope) 13 is installed has been described. Does not have to be formed.
FIG. 7 is a schematic configuration diagram showing a cross-section processing observation device according to a third embodiment of the present invention. The same number will be assigned to the same configuration as in the second embodiment, and duplicate description will be omitted. In the cross-section processing observation device 40, an optical microscope cylinder (optical microscope) 43 is independently arranged outside the sample chamber 14. Then, the coordinates of the specific observation object (attention portion) in the sample S obtained by the optical microscope cylinder (optical microscope) 43 can be read by the focused ion beam control unit and the electron beam control unit (see FIG. 1). It has a partially shared control unit 46. By providing the optical microscope cylinder (optical microscope) 43 independently outside the sample chamber 14, the degree of freedom in the installation surface of the equipment can be increased, for example, by installing each of them in a separate chamber for work.

(断面加工観察装置:第四実施形態)
図10は、本発明の第四実施形態の断面加工観察装置を示す概略構成図である。なお、第一実施形態と同様の構成には同一の番号を付し、重複する説明を省略する。断面加工観察装置50は、電子ビーム(EB)を試料Sに照射した際に、試料Sから生じたX線を検出するEDS検出器51と、このEDS検出器51を制御するEDS制御部52とを備えている。試料Sから発生するX線は、試料Sを構成する物質ごとに特有の特性X線を含み、こうした特性X線によって、試料Sを構成する物質(組成)を特定することができる。
(Cross-section processing observation device: Fourth embodiment)
FIG. 10 is a schematic configuration diagram showing a cross-sectional processing observation device according to a fourth embodiment of the present invention. The same configuration as that of the first embodiment is assigned the same number, and duplicate description will be omitted. The cross-section processing observation device 50 includes an EDS detector 51 that detects X-rays generated from the sample S when the sample S is irradiated with an electron beam (EB), and an EDS control unit 52 that controls the EDS detector 51. It has. The X-rays generated from the sample S include characteristic X-rays peculiar to each substance constituting the sample S, and the substance (composition) constituting the sample S can be specified by such characteristic X-rays.

像形成部24は、電子ビーム22の走査信号と、EDS検出器51で検出した特性X線の信号とから、試料Sの特定断面の組成像を形成する。制御部26は、複数の組成像に基づいて3次元立体組成像を構築する。なお、組成像(EDS像)とは、検出した特性X線のエネルギーから各電子ビーム照射点における試料Sの物質を特定し、電子ビーム22の照射領域の物質の分布を示したものである。 The image forming unit 24 forms a composition image of a specific cross section of the sample S from the scanning signal of the electron beam 22 and the signal of the characteristic X-ray detected by the EDS detector 51. The control unit 26 constructs a three-dimensional stereoscopic composition image based on a plurality of composition images. The composition image (EDS image) identifies the substance of the sample S at each electron beam irradiation point from the detected characteristic X-ray energy, and shows the distribution of the substance in the irradiation region of the electron beam 22.

第四実施形態の断面加工観察装置50を用いることにより、試料Sにおける特定部位の3次元組成マップを構築することができる。なお、こうした第四実施形態の断面加工観察装置50を用いて3次元組成マップを構築する方法は、後述する断面加工観察方法の第四実施形態で説明する。 By using the cross-section processing observation device 50 of the fourth embodiment, it is possible to construct a three-dimensional composition map of a specific part in the sample S. A method of constructing a three-dimensional composition map using the cross-section processing observation device 50 of the fourth embodiment will be described in the fourth embodiment of the cross-section processing observation method described later.

なお、第四実施形態の断面加工観察装置50では、EDS検出器51とともに光学顕微鏡筒13や二次電子検出器20も備えているが、光学顕微鏡筒13や二次電子検出器20を省略することもできる。 The cross-sectional processing observation device 50 of the fourth embodiment includes the optical microscope cylinder 13 and the secondary electron detector 20 together with the EDS detector 51, but the optical microscope cylinder 13 and the secondary electron detector 20 are omitted. You can also do it.

(断面加工観察方法:第一実施形態)
次に、上述した断面加工観察装置を用いた、本発明の第一実施形態の断面加工観察方法を、図1、図2を参照しつつ説明する。
図2は、断面加工観察方法の一実施形態を段階的に示したフローチャートである。
まず、対象とする試料Sを光学顕微鏡筒(光学顕微鏡)13によって観察して、試料S内に含まれる特定観察対象物(注目部分)の位置(XYZ座標)情報を取得する(位置情報取得工程S10)。試料Sは、例えば生体試料である。対象となる試料Sは、予め樹脂などで包埋して固定され、また、乾燥、脱水などの処理がなされている。こうした包埋作業や脱水作業などの生体試料作製工程は、公知の技術を用いればよい。
(Cross-section processing observation method: first embodiment)
Next, the cross-section processing observation method of the first embodiment of the present invention using the cross-section processing observation device described above will be described with reference to FIGS. 1 and 2.
FIG. 2 is a flowchart showing one embodiment of the cross-section processing observation method step by step.
First, the target sample S is observed with an optical microscope tube (optical microscope) 13, and the position (XYZ coordinates) information of the specific observation target (attention portion) contained in the sample S is acquired (position information acquisition step). S10). Sample S is, for example, a biological sample. The target sample S is embedded and fixed in advance with a resin or the like, and has been subjected to treatments such as drying and dehydration. A known technique may be used for the biological sample preparation steps such as the embedding work and the dehydration work.

このような処理をされた試料SをSEM観察すると、試料Sの表面の画像は取得できるが試料Sの内部の画像は取得できない。しかし、光学顕微鏡筒(光学顕微鏡)13によって観察すると、生物など透明性がある試料Sでは光は透過し、試料S内に光を透過しない異物や組織などの特定観察対象物(注目部分)は、コントラストの違いによって可視化できる。 When the sample S treated in this way is observed by SEM, an image of the surface of the sample S can be obtained, but an image of the inside of the sample S cannot be obtained. However, when observed with an optical microscope tube (optical microscope) 13, light is transmitted in the transparent sample S such as a living body, and a specific observation object (part of interest) such as a foreign substance or a tissue that does not transmit light is present in the sample S. , Can be visualized by the difference in contrast.

図3(A)は、試料Sを光学顕微鏡筒13によって観察した際の光学顕微鏡画像(模式図)である。試料Sの表面から所定の深さまで焦点位置を変えて観察した画像の投影図であり、視野内に現れた特定観察対象物(注目部分)C1、C2を1枚の画面に表示している。光学顕微鏡画像のXY座標を図3Aの左下に記載した座標系として、特定観察対象物C1のほぼ中心座標が(X1,Y1)で、特定観察対象物C2のほぼ中心座標が(X2,Y2)である。 FIG. 3A is an optical microscope image (schematic diagram) when the sample S is observed by the optical microscope cylinder 13. It is a projection drawing of the image observed by changing the focal position from the surface of the sample S to a predetermined depth, and the specific observation objects (parts of interest) C1 and C2 appearing in the visual field are displayed on one screen. As the XY coordinates of the optical microscope image shown in the lower left of FIG. 3A, the approximate center coordinates of the specific observation object C1 are (X1, Y1), and the approximate center coordinates of the specific observation object C2 are (X2, Y2). Is.

図3(B)は、図3(A)と同一の試料Sの同じ視野について、深さ方向を示す光学顕微鏡画像(模式図)である。試料の深さ方向をZ座標とし、試料Sの表面Z0から観察底面Znまでを表示している。光学顕微鏡筒13の焦点を表面から順次、試料Sの内部(深さ方向Z)に向かうように調整し、各焦点位置での光学顕微鏡画像をその時のZ座標と共に制御部26に記憶させる。 FIG. 3B is an optical microscope image (schematic diagram) showing the depth direction of the same field of view of the same sample S as in FIG. 3A. The depth direction of the sample is the Z coordinate, and the area from the surface Z0 of the sample S to the observation bottom surface Zn is displayed. The focal point of the optical microscope cylinder 13 is sequentially adjusted from the surface toward the inside of the sample S (depth direction Z), and the optical microscope image at each focal position is stored in the control unit 26 together with the Z coordinate at that time.

そして、光学顕微鏡筒13による光学顕微鏡画像(平面像)の取得を試料Sの表面から所定の観察底面Znまで繰り返し行なう。こうして得られた複数の光学顕微鏡画像(平面像)を合成(画像処理)することで、試料Sの3次元画像が再生され、試料Sにおける特定観察対象物(注目部分)C1,C2の深さ方向Zの存在位置(座標)を把握することができる。このように、光学顕微鏡筒(光学顕微鏡)13を用いて、XY座標を固定して光学焦点位置を変えながら試料Sを観察することで、特定観察対象物(注目部分)の試料S内における、おおよその3次元座標を明らかにすることができる。 Then, the acquisition of the optical microscope image (planar image) by the optical microscope cylinder 13 is repeated from the surface of the sample S to the predetermined observation bottom surface Zn. By synthesizing (image processing) a plurality of optical microscope images (planar images) thus obtained, a three-dimensional image of the sample S is reproduced, and the depths of the specific observation objects (parts of interest) C1 and C2 in the sample S are reproduced. The existing position (coordinates) of the direction Z can be grasped. In this way, by observing the sample S while fixing the XY coordinates and changing the optical focal position using the optical microscope cylinder (optical microscope) 13, the specific observation object (the portion of interest) in the sample S can be observed. Approximate three-dimensional coordinates can be clarified.

次に、光学顕微鏡筒(光学顕微鏡)13によって得られた特定観察対象物(注目部分)のXY座標情報を基に、集束イオンビーム鏡筒11から集束イオンビーム21を照射して、対象となる試料Sの断面形成加工を行なう(断面加工工程S11)。
図4(A)は、図3(A)に示した特定観察対象物C1と特定観察対象物C2について、SEM画像の取得領域となる特定部位(画像取得領域)を示す模式図である。図4(A)の場合、特定観察対象物C1の画像取得領域(特定部位)は、特定観察対象物C1のほぼ中心座標である(X1,Y1)を中心に、特定観察対象物の最外端部から所定の距離を加えた長さを一辺ΔX1、ΔY1とする矩形領域としている。同様に、特定観察対象物C2の画像取得領域は、座標(X2,Y2)を中心に、特定観察対象物の最外端部から所定の距離を加えた長さを一辺ΔX2、ΔY2とする矩形領域としている。
Next, based on the XY coordinate information of the specific observation object (part of interest) obtained by the optical microscope tube (optical microscope) 13, the focused ion beam 21 is irradiated from the focused ion beam lens barrel 11 to become a target. Cross-section forming processing of sample S is performed (cross-section processing step S11).
FIG. 4A is a schematic diagram showing specific parts (image acquisition areas) serving as SEM image acquisition areas for the specific observation object C1 and the specific observation object C2 shown in FIG. 3A. In the case of FIG. 4A, the image acquisition region (specific part) of the specific observation object C1 is the outermost part of the specific observation object, centered on (X1, Y1), which is approximately the center coordinates of the specific observation object C1. The length obtained by adding a predetermined distance from the end portion is defined as a rectangular region having one side ΔX1 and ΔY1. Similarly, the image acquisition region of the specific observation object C2 is a rectangle whose sides are ΔX2 and ΔY2, with the coordinates (X2, Y2) as the center and the length obtained by adding a predetermined distance from the outermost end of the specific observation object. It is an area.

この所定の長さとは、特定観察対象物を含む領域を3次元表示した時の余裕領域であり、この余裕領域が過剰に大きいと特定観察対象物の3次元像が小さくなり、余裕が無さ過ぎると断面の表示方向によっては、見にくくなる場合があるので、操作者は事前にこの余裕領域を特定観察対象物の見え方に応じて適切に定めておけば良い。例えば、特定観察対象物の投影図のXY方向のそれぞれの長さの約10%増を画像取得範囲とすれば良い。 This predetermined length is a margin area when the area including the specific observation object is displayed in three dimensions, and if this margin area is excessively large, the three-dimensional image of the specific observation object becomes small and there is no margin. If it exceeds the limit, it may be difficult to see depending on the display direction of the cross section. Therefore, the operator may appropriately determine this margin area in advance according to the appearance of the specific observation object. For example, the image acquisition range may be an increase of about 10% in each length of the projection drawing of the specific observation object in the XY directions.

図4(B)は、試料Sの深さ方向Zの投影図であり、この画像から集束イオンビーム21によって狭い間隔で試料Sの断面を露出する加工領域を決定する。ここで、図4(B)において、特定観察対象物C1が観察視野に現れる出現位置(特定観察対象物の上部)をZ11、特定観察対象物C1が観察視野から消える消滅位置(特定観察対象物の下部)をZ12とし、同様に特定観察対象物C2の出現位置Z21、特定観察対象物C2の消滅位置をZ22とする。 FIG. 4B is a projection drawing of the sample S in the depth direction Z, and from this image, a processing region for exposing the cross section of the sample S at narrow intervals is determined by the focused ion beam 21. Here, in FIG. 4B, the appearance position where the specific observation object C1 appears in the observation field (upper part of the specific observation object) is Z11, and the disappearance position where the specific observation object C1 disappears from the observation field (specific observation object). (Lower part) is Z12, and similarly, the appearance position Z21 of the specific observation object C2 and the disappearance position of the specific observation object C2 are Z22.

集束イオンビーム21により試料Sを密な間隔で薄く加工する範囲は、例えば、特定観察対象物の出現座標と消滅位置に、予め定めた長さを加えた長さと決める。所定の長さとは、特定観察対象物を含む部分を3次元表示した時の余裕領域であり、Z方向についても、例えば、特定観察対象物C1のZ方向長さ(Z12−Z11)の10%を余裕領域とし、Z座標Z11の上部、Z座標Z12の下部にこの余裕領域を加えたZ座標Z1AからZ1Bまでを加工領域とする。特定観察対象物C2についても同様に、Z座標Z2AからZ2Bまでを集束イオンビーム21により試料Sを密な等間隔で加工する断面加工範囲とする。 The range in which the sample S is thinly processed by the focused ion beam 21 at close intervals is determined, for example, as the length obtained by adding a predetermined length to the appearance coordinates and the disappearance position of the specific observation object. The predetermined length is a margin area when the portion including the specific observation object is three-dimensionally displayed, and the Z direction is also, for example, 10% of the Z direction length (Z12-Z11) of the specific observation object C1. Is a margin area, and the Z coordinate Z1A to Z1B, which is the upper part of the Z coordinate Z11 and the lower part of the Z coordinate Z12, is the processing area. Similarly, for the specific observation object C2, the Z coordinates Z2A to Z2B are set as a cross-section processing range in which the sample S is processed at close equal intervals by the focused ion beam 21.

こうした集束イオンビーム21による試料Sの加工間隔は、なるべく狭い方が特定観察対象物の構築した3次元像のZ方向の分解能が高くなる。反面、特定観察対象物がZ方向に極端に長い場合は、SEM画像の取得枚数が多くなり、蓄積される画像データが大きくなる。このため、特定観察対象物の大きさを光学顕微鏡筒(光学顕微鏡)13による観察で予め把握しておき、蓄積される画像データ容量と構築される特定観察対象物の3次元像に必要とされる分解能を予め検討したうえで、集束イオンビーム21による加工間隔を定めることが好ましい。 The narrower the processing interval of the sample S by the focused ion beam 21, the higher the resolution in the Z direction of the three-dimensional image constructed by the specific observation object. On the other hand, when the specific observation object is extremely long in the Z direction, the number of SEM images acquired increases, and the accumulated image data increases. Therefore, it is necessary to grasp the size of the specific observation object in advance by observing with the optical microscope tube (optical microscope) 13 and to obtain the accumulated image data capacity and the three-dimensional image of the specific observation object to be constructed. It is preferable to determine the processing interval by the focused ion beam 21 after examining the resolution in advance.

こうした狭い間隔での加工範囲の外側のZ座標のZ0からZ1A,Z1BからZ2A、Z2BからZnの間は、粗い間隔で短時間に集束イオンビーム21による断面加工を行えば良い。また、この領域では、特定観察対象物が存在しないことが分かっているため、SEM画像を敢えて取得する必要はない。これにより、試料Sの断面加工の時間短縮とSEM画像の記憶容量の削減を図ることができる。または、一定の間隔で断面加工を行い、特定観察対象物が存在する場合に画像取得し、対象物が存在しない場合は画像取得しないとすることによっても時間短縮及び記憶容量の削減をすることができる。 Cross-section processing by the focused ion beam 21 may be performed at a coarse interval between Z0 to Z1A, Z1B to Z2A, and Z2B to Zn on the Z coordinate outside the processing range at such a narrow interval. Further, since it is known that there is no specific observation object in this region, it is not necessary to dare to acquire the SEM image. As a result, it is possible to shorten the cross-sectional processing time of the sample S and reduce the storage capacity of the SEM image. Alternatively, it is possible to shorten the time and reduce the storage capacity by processing the cross section at regular intervals, acquiring an image when a specific observation object exists, and not acquiring an image when the object does not exist. can.

次に、加工した試料Sの断面のうち、特定観察対象物を含む特定部位のSEM画像を取得し、断面位置情報と共に保存する(断面像取得工程S12)。光学顕微鏡筒(光学顕微鏡)13による観察で得られた特定観察対象物の存在位置の座標を基に、特定観察対象物の座標を含む小領域である特定部位のSEM画像を取得する。そして、集束イオンビーム21による加工位置とSEM画像、断面内のXY座標(例えばSEM画像中心の座標)をセットで保存する。例えば、1つの断面に複数の特定観察対象物が存在する場合、それぞれの特定観察対象物を含む特定部位のSEM画像を取得する。 Next, among the cross-sections of the processed sample S, an SEM image of a specific part including a specific observation object is acquired and stored together with the cross-sectional position information (cross-sectional image acquisition step S12). Based on the coordinates of the existence position of the specific observation object obtained by the observation with the optical microscope cylinder (optical microscope) 13, an SEM image of a specific part which is a small area including the coordinates of the specific observation object is acquired. Then, the processing position by the focused ion beam 21, the SEM image, and the XY coordinates in the cross section (for example, the coordinates of the center of the SEM image) are stored as a set. For example, when a plurality of specific observation objects are present in one cross section, an SEM image of a specific part including each specific observation object is acquired.

次に、特定観察対象物の画像取得が完了したかを判断する(S13)。集束イオンビーム21による加工が予め定めた加工終了のZ座標(例えばZ1B)に達したかの判断を行う。そして、所定の到達位置に達したと判断されたら、特定観察対象物を含む特定部位の画像データの取得を完了させる。 Next, it is determined whether or not the image acquisition of the specific observation object is completed (S13). It is determined whether or not the processing by the focused ion beam 21 has reached the predetermined Z coordinate (for example, Z1B) at the end of processing. Then, when it is determined that the predetermined arrival position has been reached, the acquisition of the image data of the specific portion including the specific observation object is completed.

そして、画像取得と狭い間隔での集束イオンビーム21による加工を終了し、次の特定観察対象物の存在する領域に接近するまで、広い間隔で集束イオンビーム21による断面加工を行う。また、次の特定観察対象物が無ければ加工を終了する。 Then, the image acquisition and the processing by the focused ion beam 21 at a narrow interval are completed, and the cross-sectional processing by the focused ion beam 21 is performed at a wide interval until the area where the next specific observation object exists is approached. If there is no next specific observation object, the processing is completed.

このように、光学顕微鏡筒(光学顕微鏡)13を用いた観察によって、予め試料内の特定観察対象物の存在位置(座標)が把握できるため、特定観察対象物を含む特定部位に達するまでの加工を、広い加工幅で迅速に行なうことができる。また、特定観察対象物の存在しない部分での画像取得を行わないので、観察時間を最小限にするとともに、画像の記憶領域を小さくすることができる。また、断面の情報をより詳細に取得することができる。また、加工幅を一定としても画像取得の有無を設定できるので時間も記憶領域も小さくすることができる。 In this way, by observing with the optical microscope tube (optical microscope) 13, the existing position (coordinates) of the specific observation object in the sample can be grasped in advance, so that the processing until the specific part including the specific observation object is reached. Can be performed quickly with a wide processing width. Further, since the image is not acquired in the portion where the specific observation object does not exist, the observation time can be minimized and the storage area of the image can be reduced. In addition, cross-sectional information can be obtained in more detail. Further, even if the processing width is constant, the presence or absence of image acquisition can be set, so that the time and storage area can be reduced.

次に、断面位置情報と画像データを利用して、特定観察対象物の3次元像を構築する(立体像生成工程S14)。ここでは、例えば、コンピュータ(制御部26)を用いて、特定観察対象物を含む特定部位の複数の断面像から、画像処理プログラムによって特定観察対象物の3次元立体像を生成(構築)する。 Next, a three-dimensional image of the specific observation object is constructed by using the cross-sectional position information and the image data (three-dimensional image generation step S14). Here, for example, a computer (control unit 26) is used to generate (construct) a three-dimensional stereoscopic image of the specific observation object from a plurality of cross-sectional images of the specific portion including the specific observation object by an image processing program.

立体像生成工程S14によって得られた特定観察対象物の3次元立体像は、特定観察対象物を任意の視点から自在に観察することができ、また、任意の断面像を再生することもできるため、例えば、細胞の内部構造をSEMの分解能で観察することが可能になる。 Since the three-dimensional stereoscopic image of the specific observation object obtained in the stereoscopic image generation step S14 can freely observe the specific observation object from an arbitrary viewpoint and can reproduce an arbitrary cross-sectional image. For example, it becomes possible to observe the internal structure of a cell with SEM resolution.

上述した断面加工観察方法の変形例として、図5のフローチャートに示すように、特定観察対象物のSEM画像の取得完了後に、更に、3次元立体像構築をすべき特定観察対象物が存在するか否かの断定工程(S15)を設けることも好ましい。 As a modification of the cross-section processing observation method described above, as shown in the flowchart of FIG. 5, is there a specific observation object for which a three-dimensional stereoscopic image should be constructed after the acquisition of the SEM image of the specific observation object is completed? It is also preferable to provide a step (S15) for determining whether or not to do so.

上述した実施形態では、特定観察対象物(注目部分)が2つある場合を挙げて説明した。光学顕微鏡観察の結果、特定観察対象物がC1のみであると決めれば、集束イオンビーム21による断面加工が、Z座標Z1Bに達した時点が加工は終了する。しかし、図3、図4のように特定観察対象物が複数個ある場合、図5に示すフローチャートに従い、集束イオンビーム21による断面加工が狭い間隔の加工を終えた時点(Z座標Z1Bに達した時点)で、次に、他の特定観察対象物の有無の判断を下す(S15)。そして、他の特定観察対象物が存在する場合には、断面加工工程S11と断面像取得工程S12とを繰り返し実行する。また、他の特定観察対象物が無い場合には、特定観察対象物の立体像生成工程S14によって3次元立体像を生成する。 In the above-described embodiment, the case where there are two specific observation objects (parts of interest) has been described. As a result of optical microscope observation, if it is determined that the specific observation object is only C1, the processing is completed when the cross-sectional processing by the focused ion beam 21 reaches the Z coordinate Z1B. However, when there are a plurality of specific observation objects as shown in FIGS. 3 and 4, the cross-sectional processing by the focused ion beam 21 has reached the time when the processing at narrow intervals is completed (Z coordinate Z1B) according to the flowchart shown in FIG. At the time point), the presence or absence of another specific observation object is then determined (S15). Then, when another specific observation object is present, the cross-section processing step S11 and the cross-section image acquisition step S12 are repeatedly executed. When there is no other specific observation object, a three-dimensional stereoscopic image is generated by the stereoscopic image generation step S14 of the specific observation object.

(断面加工観察方法:第二実施形態)
上述した第一実施形態では、特定観察対象物(注目部分)が複数存在する最も簡単な例として、互いに離れて存在して、或る断面には1つの特定観察対象物しか現れない例について説明したが、本発明はこれに限定されるものでは無い。
本実施形態は、複数の特定観察対象物(注目部分)が同一のXY面内(同じZ座標)に共存する場合で、こうした試料の観察にも本発明を適用することができる。
図8は、対象となる試料を予め光学顕微鏡で観察して得られた画像情報から作成した、XY面の断面(Z視点)とXZ面(Y視点)の投影図(模式図)である。なお、図8において、図2と同じ符号は同一の構成であり、重複する説明は省略する。
(Cross-section processing observation method: second embodiment)
In the first embodiment described above, as the simplest example in which a plurality of specific observation objects (parts of interest) exist, an example in which they exist apart from each other and only one specific observation object appears in a certain cross section will be described. However, the present invention is not limited to this.
In the present embodiment, when a plurality of specific observation objects (parts of interest) coexist in the same XY plane (same Z coordinate), the present invention can be applied to the observation of such a sample.
FIG. 8 is a projection drawing (schematic diagram) of a cross section (Z viewpoint) and an XZ plane (Y viewpoint) of the XY plane, which is created from image information obtained by observing the target sample with an optical microscope in advance. Note that, in FIG. 8, the same reference numerals as those in FIG. 2 have the same configuration, and duplicate description will be omitted.

本実施形態では、特定観察対象物C3、C4が同じZ座標に共存し、片方の特定観察対象物が他方に比べて小さい。加工断面がZ座標Z31に達した時、特定観察対象物C3が断面に出現する。この時、上述した方法と同様に、特定観察対象物C3について予め定めた観察領域である特定部位のSEM像を取得し始め、かつ、予め定めたタイミングと間隔で集束イオンビーム21による断面加工を開始する。 In the present embodiment, the specific observation objects C3 and C4 coexist at the same Z coordinate, and one specific observation object is smaller than the other. When the processed cross section reaches the Z coordinate Z31, the specific observation object C3 appears in the cross section. At this time, similarly to the method described above, the SEM image of the specific portion, which is the observation region defined in advance, is started to be acquired for the specific observation object C3, and the cross-section is processed by the focused ion beam 21 at the predetermined timing and interval. Start.

特定観察対象物C3について加工と画像取得とを進める途中で、加工断面がZ座標Z41に達した時、別の特定観察対象物C4が出現する。特定観察対象物C4は事前の光学顕微鏡観察で、Z方向に長い対象物であることが予め分かっている。図8に示す例では、Z座標Z41からZ座標Z32は特定観察対象物C3と特定観察対象物C4とが同一断面に露出していることになる。 When the processed cross section reaches the Z coordinate Z41 in the middle of processing and image acquisition for the specific observation object C3, another specific observation object C4 appears. It is known in advance that the specific observation object C4 is an object long in the Z direction by observation with an optical microscope in advance. In the example shown in FIG. 8, the Z coordinate Z41 to the Z coordinate Z32 mean that the specific observation object C3 and the specific observation object C4 are exposed in the same cross section.

Z座標Z41からZ座標Z32の間の集束イオンビーム21による断面加工間隔は、特定観察対象物C3に対応した間隔で集束イオンビーム21による断面加工を行なうが、特定観察対象物C3が消滅したZ座標Z32以降も同一の加工間隔でZ座標Z42まで加工を継続させる。同一の特定観察対象物の加工間隔を途中で変えると、最終的に構築した3次元立体像に視覚的な違和感が生じるためである。また、特定観察対象物C3と特定観察対象物C4との3次元立体像を比較するような場合でも、同一の加工間隔にすることで、Z方向を同じ分解能で比較することができる。 The cross-sectional processing interval by the focused ion beam 21 between the Z coordinate Z41 and the Z coordinate Z32 is such that the cross-sectional processing by the focused ion beam 21 is performed at an interval corresponding to the specific observation object C3, but the specific observation object C3 disappears. Even after coordinate Z32, processing is continued up to Z coordinate Z42 at the same processing interval. This is because if the processing interval of the same specific observation object is changed in the middle, a visual discomfort will occur in the finally constructed three-dimensional stereoscopic image. Further, even when comparing the three-dimensional stereoscopic images of the specific observation object C3 and the specific observation object C4, the Z direction can be compared with the same resolution by setting the same processing interval.

このようにして、特定観察対象物C3と特定観察対象物C4の画像と、加工間隔の情報を保存することでこれらの情報から、特定観察対象物C3と特定観察対象物C4の3次元立体像を構築することができる。 In this way, by storing the images of the specific observation object C3 and the specific observation object C4 and the information of the processing interval, the three-dimensional stereoscopic image of the specific observation object C3 and the specific observation object C4 is obtained from these information. Can be built.

(断面加工観察方法:第三実施形態)
上述した第一実施形態では、特定観察対象物(注目部分)が1つの曲線に沿って存在する例について説明したが、本発明は、特定観察対象物が複数に枝分かれしている場合でも適用できる。また、複数の特定観察対象物が合体する場合でも適用できる。
図9は、対象となる試料を予め光学顕微鏡で観察して得られた、XY面の断面(Z方向視点)とXZ面(Y方向視点)の投影図(模式図)である。なお、図9において、図2と同じ符号は同一の構成であり、重複する説明は省略する。
(Cross-section processing observation method: Third embodiment)
In the first embodiment described above, an example in which the specific observation object (part of interest) exists along one curve has been described, but the present invention can be applied even when the specific observation object is branched into a plurality of branches. .. It can also be applied when a plurality of specific observation objects are united.
FIG. 9 is a projection drawing (schematic view) of a cross section of the XY plane (viewpoint in the Z direction) and a plane of XZ (viewpoint in the Y direction) obtained by observing the target sample with an optical microscope in advance. Note that, in FIG. 9, the same reference numerals as those in FIG. 2 have the same configuration, and duplicate description will be omitted.

特定観察対象物C5はY字のように途中で枝分かれした形状であり、それぞれの枝部の太さが一定でないことが、予め光学顕微鏡による観察で把握されている。ここで、枝部を図9のようにそれぞれC5a、C5b、C5cとする。 The specific observation object C5 has a shape that branches in the middle like a Y shape, and it is known in advance by observation with an optical microscope that the thickness of each branch is not constant. Here, the branches are C5a, C5b, and C5c, respectively, as shown in FIG.

まず、試料Sの表面(Z座標Z0)から集束イオンビーム21によって断面を作製し始め、Z座標Z5a1で特定観察対象物C5の枝部C5aが出現する。予め定めた集束イオンビーム21の加工間隔とSEM観察領域によって、加工と観察を続ける。試料Sの加工断面がZ座標Z5b1に達した時、特定観察対象物C5の枝部C5bが出現する。 First, a cross section is started to be formed from the surface of the sample S (Z coordinate Z0) by the focused ion beam 21, and the branch portion C5a of the specific observation object C5 appears at the Z coordinate Z5a1. Processing and observation are continued according to the predetermined processing interval of the focused ion beam 21 and the SEM observation area. When the processed cross section of the sample S reaches the Z coordinate Z5b1, the branch portion C5b of the specific observation object C5 appears.

この時、加工断面には、枝部C5aと枝部C5bが共存している。枝部C5aと枝部C5bが合体するZ座標Z5c1までは、枝部C5aと枝部C5bが同じ断面に共存する場合、それぞれの特定観察対象物の大きさに合わせて予め定めた観察領域(特定部位)に従って、SEM画像を取得する。集束イオンビーム21の加工間隔は、最初に出現した特定観察対象物の大きさに従い、特定観察対象物が消滅するまで維持することが望ましい。 At this time, the branch portion C5a and the branch portion C5b coexist on the processed cross section. Up to the Z coordinate Z5c1 where the branch C5a and the branch C5b are united, when the branch C5a and the branch C5b coexist in the same cross section, a predetermined observation area (specific) is set according to the size of each specific observation object. The SEM image is acquired according to the site). It is desirable that the processing interval of the focused ion beam 21 is maintained until the specific observation object disappears according to the size of the specific observation object that first appears.

また、SEMによる観察領域は、特定観察対象物の断面積に応じて適宜変更しても構わない。図9の場合、Z座標Z5C1からZ座標Z52の間は枝部C5cの断面積は徐々に小さくなるが、枝部C5cの断面積に応じて、予め定めた基準に合わせて観察領域をその都度、変更しても良い。これによって、特定観察対象物が存在しない領域の画像データ量を削減することができる。また、本実施形態の断面加工観察方法によれば、特定観察対象物の形状が不定形であっても、試料内の特定観察対象物を高分解能で3次元立体表示することができ、かつ、記録される画像データ容量を削減することができる。また、加工条件、観察条件が異なる複数の特定観察対象物が合体する場合は、加工間隔が密な方、分解能が高い方にそれぞれ合わせる。これにより複数の対象物が合体する場合でも、自動的に所望の条件の観察情報を取得することができる。 Further, the observation area by SEM may be appropriately changed according to the cross-sectional area of the specific observation object. In the case of FIG. 9, the cross-sectional area of the branch portion C5c gradually decreases between the Z coordinate Z5C1 and the Z coordinate Z52, but the observation area is set each time according to a predetermined standard according to the cross-sectional area of the branch portion C5c. , May be changed. As a result, the amount of image data in the area where the specific observation object does not exist can be reduced. Further, according to the cross-section processing observation method of the present embodiment, even if the shape of the specific observation object is indefinite, the specific observation object in the sample can be three-dimensionally displayed with high resolution in three dimensions. The amount of recorded image data can be reduced. In addition, when a plurality of specific observation objects having different processing conditions and observation conditions are combined, the processing interval is adjusted to the one with the denser processing interval and the one with the higher resolution, respectively. As a result, even when a plurality of objects are united, observation information under desired conditions can be automatically acquired.

(断面加工観察方法:第四実施形態)
図10に示した断面加工観察装置を用いた、本発明の断面加工観察方法の第四実施形態を、図10〜図14を参照しつつ説明する。
図11、図12、図13、図14は、本発明の断面加工観察方法の第四実施形態における観察手順を段階的に示した説明図である。
まず、X線CT装置において、試料SのX線CT画像を得る。
(Cross-section processing observation method: Fourth embodiment)
A fourth embodiment of the cross-section processing observation method of the present invention using the cross-section processing observation device shown in FIG. 10 will be described with reference to FIGS. 10 to 14.
11, FIG. 12, FIG. 13, and FIG. 14 are explanatory views showing step by step the observation procedure in the fourth embodiment of the cross-section processing observation method of the present invention.
First, an X-ray CT image of sample S is obtained in an X-ray CT apparatus.

そして、図11に示すように、この試料SのX線CT画像を観察して、試料S内に含まれる特定観察対象物(注目部分)C11を含む試料S内の小領域である特定部位(関心領域)Qを決定し、その3次元位置座標(XYZ座標)情報を取得する(位置情報取得工程)。 Then, as shown in FIG. 11, by observing the X-ray CT image of the sample S, a specific portion (a specific portion) which is a small region in the sample S including the specific observation object (attention portion) C11 contained in the sample S (the specific portion). The region of interest) Q is determined, and the three-dimensional position coordinate (XYZ coordinate) information thereof is acquired (position information acquisition step).

次に、特定部位Qの3次元位置座標情報に基づいて、特定観察対象物C11が存在する特定部位Qに向けて、集束イオンビーム鏡筒11から集束イオンビーム21を照射して、試料Sの特定部位Qの断面形成加工を行なう(断面加工工程)。こうした集束イオンビーム21による試料Sの断面形成加工の詳細は、第一実施形態と同様である。 Next, based on the three-dimensional position coordinate information of the specific part Q, the focused ion beam 21 is irradiated from the focused ion beam barrel 11 toward the specific part Q where the specific observation object C11 exists, and the sample S is subjected to. Perform cross-section forming processing of specific part Q (cross-section processing step). The details of the cross-section forming process of the sample S by the focused ion beam 21 are the same as those in the first embodiment.

そして、所定の間隔ごとに加工した試料Sの断面のうち、特定観察対象物C11を含む特定部位Qに向けて電子ビーム(EB)鏡筒12から電子ビーム(EB)22を照射して、試料Sの特定部位Qから発生した特性X線をEDS検出器51で検出する。そして、図12に示すように、試料Sの各断面ごとに断面組成像を構築する。この時、特定部位Qのある断面全体の組成像と、特定観察対象物C11を含む小領域の高分解能の組成像とを取得することができる。 Then, among the cross sections of the sample S processed at predetermined intervals, the electron beam (EB) 22 is irradiated from the electron beam (EB) lens barrel 12 toward the specific portion Q including the specific observation object C11, and the sample is sampled. The characteristic X-ray generated from the specific portion Q of S is detected by the EDS detector 51. Then, as shown in FIG. 12, a cross-sectional composition image is constructed for each cross-section of the sample S. At this time, it is possible to obtain a composition image of the entire cross section having the specific portion Q and a high-resolution composition image of a small region including the specific observation object C11.

例えば、図12に示す例では、特定部位Qに3つの断面F1,F2,F3を予め設定して、このそれぞれの断面を集束イオンビーム21によって加工する。そして、断面F1,F2,F3のそれぞれにおいて、断面全体の組成像K1a,K2a,K3aと、特定観察対象物C11を含む小領域の高分解能断面組成像K1b,K2b,K3bを取得する。図12の例では、矩形に設定された特定部位Qの断面F1,F2,F3において、断面全体の組成像K1a,K2a,K3aには、成分G1,G2,G3の中に特定観察対象物(注目部分)C11がある。そして、高分解能断面組成像K1b,K2b,K3bによれば、特定観察対象物C11は、成分G4,G5,G6から構成されている。 For example, in the example shown in FIG. 12, three cross sections F1, F2, and F3 are preset in the specific portion Q, and each cross section is processed by the focused ion beam 21. Then, in each of the cross sections F1, F2, and F3, the composition images K1a, K2a, and K3a of the entire cross section and the high resolution cross-sectional composition images K1b, K2b, and K3b of a small region including the specific observation object C11 are acquired. In the example of FIG. 12, in the cross sections F1, F2, and F3 of the specific portion Q set to be rectangular, the composition images K1a, K2a, and K3a of the entire cross section have the specific observation objects (specific observation objects) in the components G1, G2, and G3. Attention part) There is C11. Then, according to the high-resolution cross-sectional composition images K1b, K2b, and K3b, the specific observation object C11 is composed of the components G4, G5, and G6.

なお、こうした特定部位Qの各加工断面においては、断面全体の断面組成像だけを取得してもよく、また、2つ以上の特定観察対象物がある場合には、2箇所以上の高分解能断面組成像を取得することもできる。また、特定部位Qの全ての加工断面で断面組成像を取得しても、あるいは、特定の断面だけ、選択的に断面組成像を取得してもよい。 In each processed cross section of the specific portion Q, only the cross-sectional composition image of the entire cross section may be acquired, and when there are two or more specific observation objects, two or more high-resolution cross sections are obtained. It is also possible to obtain a composition image. Further, the cross-sectional composition image may be acquired for all the processed cross sections of the specific portion Q, or the cross-sectional composition image may be selectively acquired only for the specific cross section.

以上の様な工程によって、例えば、図13に示すように、特定部位Qの3つの断面F1,F2,F3において、断面全体の組成像K1a,K2a,K3aと、特定観察対象物C11を含む小領域の高分解能断面組成像K1b,K2b,K3bが得られる。 By the above steps, for example, as shown in FIG. 13, in the three cross sections F1, F2, F3 of the specific portion Q, the composition images K1a, K2a, K3a of the entire cross section and the small object including the specific observation object C11 are included. High-resolution cross-sectional composition images K1b, K2b, and K3b of the region can be obtained.

次に、試料Sの断面位置情報と、それぞれの断面F1,F2,F3での組成像K1a,K2a,K3aと、高分解能断面組成像K1b,K2b,K3bとを利用して、図14に示すような特定観察対象物を含む特定部位Qの3次元立体組成像Rを構築する(立体像生成工程)ここでは、例えば、コンピュータ(制御部26)を用いて、画像処理プログラムによって特定観察対象物を含む特定部位Qの3次元立体組成像を生成(構築)する。 Next, FIG. 14 shows the cross-sectional position information of the sample S, the composition images K1a, K2a, and K3a in the respective cross-sections F1, F2, and F3, and the high-resolution cross-sectional composition images K1b, K2b, and K3b. A three-dimensional three-dimensional composition image R of a specific part Q including such a specific observation object is constructed (three-dimensional image generation step). Here, for example, a computer (control unit 26) is used by an image processing program to construct a specific observation object. A three-dimensional three-dimensional composition image of a specific part Q including the above is generated (constructed).

立体像生成工程によって得られた3次元立体組成像Rは、特定部位Q全体の成分を示す立体組成像と、特定観察対象物を高分解能で分析した高分解能立体組成像とを合成したものからなる。 The three-dimensional composition image R obtained by the three-dimensional image generation step is obtained by synthesizing a three-dimensional composition image showing the components of the entire specific part Q and a high-resolution three-dimensional composition image obtained by analyzing a specific observation object with high resolution. Become.

以上のように、それぞれの加工断面において特性X線をEDS検出器51で検出することにより断面組成像を取得することで、特定観察対象物を含む特定部位Qの3次元立体組成像Rを得ることができる。 As described above, by acquiring the cross-sectional composition image by detecting the characteristic X-rays in each processed cross section with the EDS detector 51, the three-dimensional three-dimensional composition image R of the specific portion Q including the specific observation object is obtained. be able to.

本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれると同様に、特許請求の範囲に記載された発明とその均等の範囲に含まれるものである。 Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

10 断面加工観察装置
11 集束イオンビーム(FIB)鏡筒
12 電子ビーム(EB)鏡筒
13 光学顕微鏡筒(光学顕微鏡)13
26 制御部
51 EDS検出器
10 Cross-section processing observation device 11 Focused ion beam (FIB) lens barrel 12 Electron beam (EB) lens barrel 13 Optical microscope tube (optical microscope) 13
26 Control 51 EDS detector

Claims (6)

観察対象の試料全体を光学顕微鏡で観察して、前記試料に含まれる特定観察対象物の前記試料内におけるおおよその3次元位置座標情報を取得する位置情報取得工程と、
前記3次元位置座標情報に基づいて、前記試料のうち前記特定観察対象物が存在する特定部位に向けて集束イオンビームを照射して、該特定部位の断面を露出させる断面加工工程と、
前記断面に電子ビームを照射して、前記特定観察対象物を含む所定の大きさの領域の画像を取得する断面像取得工程と、
前記断面加工工程および前記断面像取得工程を所定間隔で所定方向に沿って複数回繰返し行い、取得した複数の前記画像から前記特定観察対象物を含む3次元立体像を構築する立体像生成工程と、を有することを特徴とする断面加工観察方法。
The entire sample to be observed by observing with an optical microscope, a position information acquisition step of acquiring the approximate three-dimensional position coordinate information within said sample of a particular observation object contained in the sample,
Based on the three-dimensional position coordinate information, a cross-section processing step of irradiating a specific portion of the sample in which the specific observation object is present with a focused ion beam to expose the cross section of the specific portion.
A cross-sectional image acquisition step of irradiating the cross-section with an electron beam to acquire an image of a region of a predetermined size including the specific observation object, and a cross-sectional image acquisition step.
The cross section processing step and the cross-sectional image acquisition process repeated several times along a predetermined direction at a predetermined interval, generating stereoscopic images to construct a three-dimensional image including the specific observation object from a plurality of pre-outs image acquired A method for observing cross-section processing, which comprises a process.
前記特定観察対象物は複数種類設定され、それぞれの特定観察対象物ごとに前記断面加工工程を行うことを特徴とする請求項1記載の断面加工観察方法。 The cross-section processing observation method according to claim 1, wherein a plurality of types of the specific observation object are set, and the cross-section processing step is performed for each specific observation object. 前記光学顕微鏡として、共焦点実体顕微鏡を用いることを特徴とする請求項1または2記載の断面加工観察方法。 The cross-section processing observation method according to claim 1 or 2, wherein a confocal stereomicroscope is used as the optical microscope. 前記断面像取得工程において、前記断面のエネルギー分散型X線検出により前記特定観察対象物を含む前記特定部位の断面組成像を更に取得し、
前記立体像生成工程において、取得した複数の前記断面組成像から前記特定観察対象物を含む3次元立体組成像を構築することを特徴とする請求項1または2記載の断面加工観察方法。
In the cross-sectional image acquisition step, a cross-sectional composition image of the specific portion including the specific observation object is further acquired by energy dispersion type X-ray detection of the cross section.
The cross-section processing observation method according to claim 1 or 2, wherein a three-dimensional three-dimensional composition image including the specific observation object is constructed from the plurality of acquired cross-section composition images in the three-dimensional image generation step.
特定観察対象物を含む試料を載置する試料台と、
前記試料に集束イオンビームを照射する集束イオンビーム鏡筒と、
前記試料に電子ビームを照射する電子ビーム鏡筒と、
前記試料を光学的に観察する光学顕微鏡筒と、
前記試料から発生する二次電子を検出する二次電子検出器又は反射電子を検出する反射電子検出器と、
前記光学顕微鏡筒によって前記試料内における前記特定観察対象物の存在位置を特定して、前記試料のうち前記特定観察対象物が存在する特定部位に向けて前記集束イオンビーム鏡筒から集束イオンビームを照射して断面を露出させ、前記断面に前記電子ビーム鏡筒から電子ビームを照射して前記特定観察対象物を含む所定の大きさの領域の画像を取得させ、前記画像から前記特定観察対象物を含む特定部位の3次元立体像を構築する制御部と、
を備えたことを特徴とする断面加工観察装置。
A sample table on which a sample containing a specific observation object is placed, and
A focused ion beam lens barrel that irradiates the sample with a focused ion beam,
An electron beam lens barrel that irradiates the sample with an electron beam,
An optical microscope tube for optically observing the sample and
A secondary electron detector that detects secondary electrons generated from the sample or a backscattered electron detector that detects backscattered electrons,
The position of the specific observation object in the sample is specified by the optical microscope cylinder, and the focused ion beam is emitted from the focused ion beam lens barrel toward the specific part of the sample in which the specific observation object is present. The cross section is exposed by irradiation, and the cross section is irradiated with an electron beam from the electron beam lens barrel to acquire an image of a region of a predetermined size including the specific observation object, and the specific observation object is obtained from the image . A control unit that constructs a three-dimensional stereoscopic image of a specific part including
A cross-section processing observation device characterized by being equipped with.
前記試料から発生する特性X線を検出するEDS検出器を備え、前記制御部は、前記特定部位の3次元立体組成像を構築することを特徴とする請求項5記載の断面加工観察装置。 The cross-section processing observation device according to claim 5, further comprising an EDS detector that detects characteristic X-rays generated from the sample, and the control unit constructs a three-dimensional three-dimensional composition image of the specific portion.
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