JP6713683B2 - High resolution optical microscopy and particle size estimation - Google Patents
High resolution optical microscopy and particle size estimation Download PDFInfo
- Publication number
- JP6713683B2 JP6713683B2 JP2016050941A JP2016050941A JP6713683B2 JP 6713683 B2 JP6713683 B2 JP 6713683B2 JP 2016050941 A JP2016050941 A JP 2016050941A JP 2016050941 A JP2016050941 A JP 2016050941A JP 6713683 B2 JP6713683 B2 JP 6713683B2
- Authority
- JP
- Japan
- Prior art keywords
- optical microscope
- particle size
- thin film
- contrast
- measurement method
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002245 particle Substances 0.000 title claims description 34
- 238000000399 optical microscopy Methods 0.000 title claims 2
- 230000003287 optical effect Effects 0.000 claims description 37
- 239000010409 thin film Substances 0.000 claims description 27
- 238000000691 measurement method Methods 0.000 claims description 20
- 238000000879 optical micrograph Methods 0.000 claims description 15
- 239000010408 film Substances 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 10
- 238000011088 calibration curve Methods 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 4
- 239000003575 carbonaceous material Substances 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- 150000004767 nitrides Chemical class 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 238000003384 imaging method Methods 0.000 claims 1
- 238000005286 illumination Methods 0.000 description 9
- 230000005540 biological transmission Effects 0.000 description 8
- 239000000758 substrate Substances 0.000 description 6
- 238000005259 measurement Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 239000010419 fine particle Substances 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 238000000089 atomic force micrograph Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
Images
Landscapes
- Length Measuring Devices By Optical Means (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Microscoopes, Condenser (AREA)
Description
本発明は、高分解能光学顕微鏡計測法に関し、特に、従来の光学顕微鏡の解像限界を越える長径1μm未満の微小材料を可視化可能にした高分解能光学顕微鏡計測法に関する。 The present invention relates to a high-resolution optical microscope measurement method, and more particularly to a high-resolution optical microscope measurement method capable of visualizing a minute material having a major axis of less than 1 μm, which exceeds the resolution limit of a conventional optical microscope.
従来、光学顕微鏡を用い、スライドガラス等の透明基板の上に材料を分散し、透過光または落射光等により、コントラストをつけて、十分に大きい物体は直接画像から寸法を測定し、小さなものはコントラストを利用して校正曲線から寸法を推定することが行われてきた。また、割れやすく厚く(約1mm)てかさばるスライドガラスに代えて厚さ50〜300μm程度の膜状高分子支持体を透明基板に用いる(特許文献1参照)ことも行われているが、従来の光学顕微鏡を用いた計測法では用いる可視光の波長(略380nm〜780nm)から自ずと解像限界があり、1μm未満の物体を確実に識別することはできなかった(なお光を当てると点光源になるような物体であれば、その存在を識別できる場合があった)。 Conventionally, using an optical microscope, the material is dispersed on a transparent substrate such as a slide glass, contrast is added by transmitted light or incident light, and the size of a sufficiently large object is measured directly from the image. It has been practiced to use contrast to estimate dimensions from calibration curves. Further, it is also known to use a membrane-like polymer support having a thickness of about 50 to 300 μm for a transparent substrate (see Patent Document 1) in place of a slide glass which is fragile and thick (about 1 mm) and bulky (see Patent Document 1). In the measurement method using an optical microscope, there was a natural resolution limit from the wavelength of visible light used (approximately 380 nm to 780 nm), and it was not possible to reliably discriminate objects smaller than 1 μm. In some cases, the existence of such an object could be identified.)
本発明が解決しようとする課題は、従来の光学顕微鏡の解像限界を越えた、長径1μm未満のオーダーの微小物体を確実に高いコントラストで識別可能とする光学顕微鏡計測法を提供することにある。 The problem to be solved by the present invention is to provide an optical microscope measurement method capable of reliably identifying a minute object having a major axis of less than 1 μm, which exceeds the resolution limit of a conventional optical microscope, with high contrast. ..
そこで上記課題を解決するために、本発明者等は、透過型電子顕微鏡用の膜付きグリッド(特許文献2参照)などに用いられている超薄膜に着目し、鋭意研究の結果驚くべきことに、100nm以下の薄膜または単層原子膜(例えば、グラフェン膜等)上に長径1μm未満の試料を乗せることにより、超高解像度の画像を得ることが可能となる光学顕微鏡計測法を開発した。厚さ100nm以下の薄膜を透明基板に利用すると、基板の効果を非常に小さくでき、基板上の長径1μm未満の試料粒子のコントラストを上げることができると考えられ、このため、さらに膜の均質化(厚み等)をはかれば、微細な長径500nm以下の粒子であっても、判別が可能になる
すなわち、本発明は、膜厚100nm以下の光透過性の薄膜上に長径1μm未満の被測定物体を分散させ、光学顕微鏡の対物レンズを通して光学顕微鏡画像を得ることにより長径1μm未満の被測定物体を画像化する高分解能光学顕微鏡計測法である。
また、本発明は、上記高分解能光学顕微鏡計測法において、前記薄膜の材料は、炭素系素材、薄膜シリコン、酸化物、窒化物、単原子薄膜、または、層状化合物であることを特徴とする。
また、本発明は、上記高分解能光学顕微鏡計測法において、前記対物レンズと前記薄膜の間は、大気、真空、または、前記薄膜と屈折率の異なる溶媒であることを特徴とする。
また本発明は、上記高分解能光学顕微鏡計測法を用いて、予め、既知の複数の粒径の標準試料について各粒径毎の光学顕微鏡画像を得て、各粒径毎の光学顕微鏡画像のコントラストの違いから粒径とコントラストの関係を表す検量線を求めておき、次に上記高分解能光学顕微鏡計測法を用いて、粒径1μm未満の被測定試料について光学顕微鏡画像を得、当該光学顕微鏡画像からコントラストを求め、求めたコントラストを予め求めていた前記検量線に当てはめることにより粒径を求める粒径推定法である。
Therefore, in order to solve the above problems, the present inventors have focused their attention on an ultra-thin film used in a grid with a film for a transmission electron microscope (see Patent Document 2), and surprisingly as a result of earnest research. , An optical microscope measurement method has been developed which makes it possible to obtain an ultra-high resolution image by placing a sample with a major axis of less than 1 μm on a thin film of 100 nm or less or a single-layer atomic film (eg, graphene film). When a thin film having a thickness of 100 nm or less is used as a transparent substrate, it is considered that the effect of the substrate can be made extremely small and the contrast of sample particles with a major axis of less than 1 μm on the substrate can be increased. By measuring (thickness, etc.), it becomes possible to discriminate even fine particles having a major axis of 500 nm or less. That is, the present invention is to measure a particle having a major axis of less than 1 μm on a light-transmissive thin film having a thickness of 100 nm or less. It is a high-resolution optical microscope measurement method in which an object is dispersed and an optical microscope image is obtained through an objective lens of an optical microscope to image an object to be measured having a major axis of less than 1 μm.
In the high resolution optical microscope measurement method of the present invention, the material of the thin film is a carbon-based material, thin film silicon, oxide, nitride, a monatomic thin film, or a layered compound.
Further, in the high resolution optical microscope measurement method of the present invention, the space between the objective lens and the thin film is atmospheric air, vacuum, or a solvent having a refractive index different from that of the thin film.
Further, the present invention, by using the above high-resolution optical microscope measurement method, in advance, obtain an optical microscope image for each particle size for a standard sample of a plurality of known particle size, the contrast of the optical microscope image for each particle size A calibration curve representing the relationship between the particle size and the contrast is obtained in advance, and then the high resolution optical microscope measurement method is used to obtain an optical microscope image of the sample to be measured having a particle size of less than 1 μm. This is a particle size estimation method for obtaining the particle size by obtaining the contrast from the above and applying the obtained contrast to the previously obtained calibration curve.
本発明では、長径1μm未満の材料について、光学顕微鏡を用いて計測できるので、従来の高価で大がかりで操作も煩雑な電子顕微鏡を用いる必要がなく、安価で操作も簡便な光学顕微鏡での計測が実現できる。
また、予め複数の既知粒径の標準試料を用いて計測し粒径とコントラストの関係を求めておけば、被測定試料のコントラストにより粒径を求めることができる。
In the present invention, since a material having a major axis of less than 1 μm can be measured using an optical microscope, it is not necessary to use a conventional expensive, large-scale, and complicated operation electron microscope, and measurement with an optical microscope that is inexpensive and easy to operate can be performed. realizable.
Further, if the relationship between the particle size and the contrast is obtained in advance by using a plurality of standard samples having known particle sizes, the particle size can be obtained from the contrast of the sample to be measured.
本発明の計測法は、非常に薄い100nm以下の薄膜(例えば透過電子顕微鏡用の膜付グリッドなど)や単層原子膜(例えばグラフェン膜など)上に被測定試料を乗せることにより、超高解像度の光学顕微鏡画像を得ることを可能としたものである。本発明の計測法によれば、可視光の波長(略300nm〜1100nm)により従来光学顕微鏡の解像限界を越え不可能と考えられていた、長径1μm未満の被測定試料(粒子等)に対する超高解像度の光学顕微鏡画像が得られ、利用する薄膜は、膜の厚さが均質なものを用いることで、膜と材料のコントラストを上げることができる。 The measurement method of the present invention is a super-high-resolution method by placing a sample to be measured on a very thin thin film of 100 nm or less (for example, a grid with a film for a transmission electron microscope) or a monolayer atomic film (for example, a graphene film). It is possible to obtain an optical microscope image of. According to the measurement method of the present invention, the wavelength of visible light (approximately 300 nm to 1100 nm) is considered to be impossible to exceed the resolution limit of the conventional optical microscope, and it is possible to measure a sample (particle or the like) having a major axis of less than 1 μm. A high-resolution optical microscope image can be obtained and the thin film to be used has a uniform film thickness, whereby the contrast between the film and the material can be increased.
図1は、本発明の光学顕微鏡計測法を落射式および透過式光学顕微鏡を用いて実現した説明図である。図1の左側図(落射式)では、100nm以下の薄膜上に乗せた長径150nmの物体(被測定試料)に上から落射光源の光を照射し、物体で光を散乱または吸収させ、対物レンズを通して撮像素子(CCD等)に結像させ顕微鏡画像を得るものである。図1の右側図(透過式)では、100nm以下の薄膜上に乗せた長径150nmの物体(被測定試料)に、下から透過光源の光を照射し、物体で光を散乱または吸収させ、対物レンズを通して撮像素子(CCD等)に結像させ光学顕微鏡画像を得るものである。
なお、落射式と透過式について説明したが、その他の微分干渉モード、偏光顕微鏡などの各種モードの光学顕微鏡で実現可能であることはいうまでもない。
さらに、予め複数の粒径について標準粒子を用いて得た顕微鏡画像から、粒径とコントラストの校正曲線を求めておき、被測定試料の顕微鏡画像から前記校正曲線を用いて粒径を推定することもできる。
図2は、対物レンズと薄膜間について、大気、真空、または、薄膜と異なる屈折率の溶媒を入れる場合のいずれでも可能であることを示した図である。なお、図2の左側図が落射式、右側図が透過式によるものである。
FIG. 1 is an explanatory view in which the optical microscope measuring method of the present invention is realized by using an epi-illumination type and a transmission type optical microscope. In the left view of Fig. 1 (epi-illumination type), an object with a long diameter of 150 nm (sample to be measured) placed on a thin film of 100 nm or less is irradiated with light from an epi-illumination source from above, and the light is scattered or absorbed by the object lens. A microscope image is obtained by forming an image on an image sensor (CCD or the like) through. In the right view (transmission type) of FIG. 1, an object (measurement sample) with a long diameter of 150 nm placed on a thin film of 100 nm or less is irradiated with light from a transmission light source from below, and the light is scattered or absorbed by the object, An optical microscope image is obtained by forming an image on an image sensor (CCD or the like) through a lens.
Although the epi-illumination type and the transmission type have been described, it goes without saying that they can be realized by other differential interference modes and optical microscopes of various modes such as a polarization microscope.
Furthermore, a calibration curve of particle size and contrast is obtained in advance from a microscope image obtained by using standard particles for a plurality of particle sizes, and the particle size is estimated from the microscope image of the sample to be measured using the calibration curve. Can also
FIG. 2 is a diagram showing that it is possible to use air, vacuum, or a solvent having a refractive index different from that of the thin film between the objective lens and the thin film. 2 is based on the epi-illumination type, and the right side is based on the transmission type.
その他の実施形態としては、以下のものが挙げられる。
使用する薄膜の材料は、炭素系素材、薄膜シリコン、酸化物、窒化物をはじめする、薄膜状態で光を透過する材料であれば使用できる。
単原子薄膜や層状化合物の層(100層以下ただし総厚100nm以下)上に、長径1μm未満の寸法の構造体を含む材料を分散させ、光学レンズを通して撮像素子に結像することにより、微細な材料を画像化することもできる。
溶液中に100nm以下薄膜の支持基板を固定することにより、環境中での観察が可能である。
暗視野照明や偏光を利用することにより、コントラスト・分解能を向上できる。
Other embodiments include the following.
The material of the thin film to be used may be any material that transmits light in a thin film state, such as carbon-based material, thin film silicon, oxide, and nitride.
A material containing a structure having a major axis of less than 1 μm is dispersed on a layer of a monatomic thin film or a layered compound (100 layers or less, but a total thickness of 100 nm or less), and an image is formed on an image sensor through an optical lens to form a fine image. The material can also be imaged.
By fixing a supporting substrate having a thin film of 100 nm or less in the solution, observation in the environment is possible.
The contrast and resolution can be improved by using dark field illumination and polarized light.
(実測例)
図3は、粒径150nmのポリスチレンラテックス粒子(PSL粒子)を膜厚30nmのフォルムバール膜上にのせ、落射光源を利用する汎用の光学顕微鏡(図3左図参照)で、対物レンズを通して撮像素子(CCD等)上に孤立粒子の画像を得ることができた光学顕微鏡画像(図3中央図参照)である。図3右図は、同じ試料のほぼ同一視野に対して原子間力顕微鏡で得られた画像である。光学顕微鏡画像と原子間力顕微鏡の画像とを対比すれば、両者で対応する位置に粒子画像が得られており、本発明の光学顕微鏡計測法により、従来解像限界を越え実現不可能と考えられていた長径1μm未満の被測定試料の光学顕微鏡画像が得られることが確認された。
(Measurement example)
Fig. 3 shows a general-purpose optical microscope (see left figure in Fig. 3) that uses a polystyrene light-emitting particle (PSL particle) with a particle size of 150 nm on a Formvar film with a film thickness of 30 nm and uses an epi-illumination light source. It is an optical microscope image (see the central view of FIG. 3) in which an image of isolated particles can be obtained on (CCD or the like). The right diagram of FIG. 3 is an image obtained by an atomic force microscope for almost the same visual field of the same sample. By comparing the image of the optical microscope and the image of the atomic force microscope, the particle images are obtained at the corresponding positions in both, and it is considered that the conventional optical microscope measurement method exceeds the resolution limit and cannot be realized. It was confirmed that an optical microscope image of the measured sample having a major axis of less than 1 μm was obtained.
本発明によれば、光学顕微鏡で観察・定量可能な粒径の範囲を、従来の解像限界を越える1μm未満にまで広げることができ、研磨剤や工業用粒子等の微粒子の計測を迅速に行える。
また、電子顕微鏡・原子間力顕微鏡で精密な測定をする前に、簡単に、微細な粒子等の存在を位置合わせ用光学顕微鏡を用いて確認できる。
According to the present invention, the range of particle size that can be observed and quantified with an optical microscope can be expanded to less than 1 μm, which exceeds the conventional resolution limit, and measurement of fine particles such as abrasives and industrial particles can be performed quickly. You can do it.
In addition, the presence of fine particles and the like can be easily confirmed using an optical microscope for alignment before performing precise measurement with an electron microscope or an atomic force microscope.
Claims (4)
次に、請求項1〜3のいずれかに記載の高分解能光学顕微鏡計測法を用いて、粒径1μm未満の被測定試料について光学顕微鏡画像を得、当該光学顕微鏡画像のコントラストを求め、求めたコントラストを予め求めていた前記検量線に当てはめることにより粒径を求める粒径推定法。 Using the high-resolution optical microscope measurement method according to any one of claims 1 to 3, an optical microscope image for each particle size is obtained in advance for standard samples having a plurality of known particle sizes, and for each particle size. A calibration curve representing the relationship between particle size and contrast is obtained from the difference in contrast of the optical microscope image,
Next, using the high-resolution optical microscope measurement method according to any one of claims 1 to 3, an optical microscope image of a sample to be measured having a particle size of less than 1 µm was obtained, and the contrast of the optical microscope image was obtained and obtained. A particle size estimation method for determining the particle size by applying the contrast to the previously calculated calibration curve.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016050941A JP6713683B2 (en) | 2016-03-15 | 2016-03-15 | High resolution optical microscopy and particle size estimation |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016050941A JP6713683B2 (en) | 2016-03-15 | 2016-03-15 | High resolution optical microscopy and particle size estimation |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2017167263A JP2017167263A (en) | 2017-09-21 |
JP6713683B2 true JP6713683B2 (en) | 2020-06-24 |
Family
ID=59913409
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2016050941A Active JP6713683B2 (en) | 2016-03-15 | 2016-03-15 | High resolution optical microscopy and particle size estimation |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP6713683B2 (en) |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3981696B2 (en) * | 1998-07-28 | 2007-09-26 | 株式会社日立製作所 | Defect inspection apparatus and method |
JP2004138404A (en) * | 2002-10-15 | 2004-05-13 | Kansai Tlo Kk | Deep ultraviolet ray-corresponding nearfield optical microscope |
JP2010002300A (en) * | 2008-06-20 | 2010-01-07 | Jeol Ltd | Sample holder, sample inspection device and sample inspecting method |
JP2010107336A (en) * | 2008-10-30 | 2010-05-13 | Mitsubishi Chemicals Corp | Evaluation method of porous aggregate |
KR101211092B1 (en) * | 2010-12-28 | 2012-12-12 | 한국과학기술연구원 | Bio channel system |
-
2016
- 2016-03-15 JP JP2016050941A patent/JP6713683B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
JP2017167263A (en) | 2017-09-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Wang et al. | Single-shot isotropic differential interference contrast microscopy | |
Mudanyali et al. | Wide-field optical detection of nanoparticles using on-chip microscopy and self-assembled nanolenses | |
Edwards et al. | Diffraction phase microscopy: monitoring nanoscale dynamics in materials science | |
Li et al. | Label-free super-resolution imaging of adenoviruses by submerged microsphere optical nanoscopy | |
Siyushev et al. | Monolithic diamond optics for single photon detection | |
Liu et al. | Characterization of graphene layers using super resolution polarization parameter indirect microscopic imaging | |
Cao et al. | Localized surface plasmon resonance of single silver nanoparticles studied by dark-field optical microscopy and spectroscopy | |
Chen et al. | Depolarization effects from nanoimprinted grating structures as measured by Mueller matrix polarimetry | |
Attota et al. | Resolving three-dimensional shape of sub-50 nm wide lines with nanometer-scale sensitivity using conventional optical microscopes | |
Khademhosseinieh et al. | Lensfree on-chip imaging using nanostructured surfaces | |
Tiefenauer et al. | Monolayer graphene coupled to a flexible plasmonic nanograting for ultrasensitive strain monitoring | |
Attota et al. | Parameter optimization for through-focus scanning optical microscopy | |
Flatabø et al. | Exploring proximity effects and large depth of field in helium ion beam lithography: large-area dense patterns and tilted surface exposure | |
Cui et al. | Quantitative differential interference contrast microscopy based on structured-aperture interference | |
JP6713683B2 (en) | High resolution optical microscopy and particle size estimation | |
kiran Attota | Through-focus scanning optical microscopy applications | |
De Caro et al. | Ptychographic imaging of branched colloidal nanocrystals embedded in free-standing thick polystyrene films | |
Segal-Peretz et al. | Metrology of DSA process using TEM tomography | |
Jang et al. | Design and fabrication of wire grid polarizer by nanoimprinting and glancing angle deposition processes | |
Buß et al. | Sub-wavelength surface gratings for light redirection in transparent substrates | |
Attota | Nanoscale Measurements with the TSOM Optical Method | |
Sharbidre et al. | Comparison of existing methods to identify the number of graphene layers | |
Hu et al. | Straining of atomically thin WSe2 crystals: Suppressing slippage by thermal annealing | |
Nevels et al. | Novel optical metrology for inspection of nanostructures fabricated by substrate conformal imprint lithography | |
Chander | Characterization of dental materials |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20181011 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20190626 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20190724 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20190904 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200108 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20200228 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20200527 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20200528 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 6713683 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |