新技術説明会 ラマン分光 必見! AFM- ラマンによるナノイメージの世界 株式会社堀場製作所
2013 HORIBA Scientific. All rights reserved. Ultra fast simultaneous AFM and hyper-spectral imaging: chemical and physical investigation of nano-materials made fast and easy. Ultra fast AFM- imaging Emmanuel Leroy AFM- Product Manager 256x256pts simultaneous topography and composite image of graphene Multi-modal imaging Microscopy today is much more than looking at a magnified image Multi-modal imaging Microscopy today is much more than looking at a magnified image It s about multiple ways of looking at a given sample. 1
Why AFM- Scanning Probe Microscopy (SPM) and specifically Atomic Force Microscopy (AFM) have made nanoscale imaging an affordable reality Cheaper than SEM and TEM Much less sample preparation. Very versatile Atomic Force Microscopy (AFM) came as an easier to use and flexible technique With AFM s popularity came many more modes of operation, providing much more than topography Elasticity / plasticity of materials, Young s modulus Conductivity/Resistivity (C-AFM), Surface Potential / Kelvin Probe (SKM, KPFM) Graphene on copper foil, AFM and KPFM images Magnetic Force (MFM) Why AFM- AFM, the most common SPM technique, is ideal for imaging physical parameters, but lacks sensitivity to chemical structure and composition 2
Spectroscopy: spectra to images Spectroscopy, especially IR and, are much better suited for label-free chemical analysis Spectroscopy: spectra to images but spectra are still pretty obscure for most people Spectroscopy: spectra to images People want things they can make sense of: people want images! Why AFM- AFM- brings chemical imaging and nanoscale physical characteristics imaging together. This is multi-modal imaging pushed beyond optical microscopy and to the nano scale Why TERS? spectroscopy brings highly specific chemical information, but spatial resolution is limited by Abbe s law of light diffraction. 12000 10000 8000 6000 4000 2000 876.0 1062.5 1128.3 1168.3 1264.1 1294.2 1369.4 1415.4 1439.5 1461.6 1641.5 0 800 1000 1200 1400 1600 Why TERS? Super-resolution techniques have brought chemical information down to ~30nm scale, but they all rely on fluorescent labels. SPM techniques can provide many physical properties at the nano scale (mechanical, electrical, magnetic ), but no chemical specificity Tip-Enhanced brings the prospect of label-free chemical imaging at the nano scale. Deckert et al. 2008 3
Instrumental Challenges Combining such different techniques as SPM and Spectroscopy is challenging. The common approach has been to perform co-localized measurements in sequence: First Spectroscopy to find an area of interest, then AFM for nanoscale characterization, or vice-versa: find a physical structure of interest to determine chemical structure with spectroscopy Challenges: Optics Tighter spot on the tip = better contrast Higher collection efficiency = better signal In order to illuminate the probe tip, there needs to be proper optical access for such high numerical aperture objective lens Challenges: Optics Tighter spot on the tip = better contrast The spot size is directly dependent on the NA as R = 0.6* /NA Challenges: Optics Higher collection efficiency = better signal The collection efficiency depends on the NA 2! Challenges: Optics & Sample Best solution: Inverted microscope SPM on top, bottom access for High NA objective up to 1.49 Samples need to be transparent 4
Challenges: Optics & Sample For opaque samples: Top illumination can accept fairly high NA objectives (0.7) Shadowing from the cantilever is an issue and the probe needs to be protruded Challenges: AFM diode It is also important to note that the AFM feedback requires a diode laser, which may interfere with the spectroscopy measurements: An AFM diode in the IR is required to perform AFM- in the full range of VIS-NIR lasers available. The diode must not use the same beam path as the spectroscopy laser, or independent alignment becomes very cumbersome Fast simultaneous AFM- IR AFM Diode (no interference) Access to change sample and tip without moving the head Auto-cantilever alignment and tuning (comes back to the same place) Top access with 0.7NA objective, side access with up to 0.7NA for TERS Visual confirmation of alignment in all ports Fast simultaneous AFM- Powerful software package 1300nm Auto alignment Video viewing of tip and laser Easy tip exchange High NA access IR AFM Diode (no interference) Access to change sample and tip without moving the head Auto-cantilever alignment and tuning (comes back to the same place) Top access with 0.7NA objective, side access with up to 0.7NA for TERS Visual confirmation of alignment in all ports Integrated multivariate module High level analysis at a touch of a button PCA MCR HCA DCA KnowItAll HORIBA Edition Fast chemical identification HORIBA spectral database (>1750 spectra) 5
Added advantage Not only integrates a powerful, high resolution AFM, with high frequency scanner, little sensitive to vibrations Also combines powerful microscope that can be used as standalone (3 instruments in one) Added advantage: real-time autofocus The AFM also acts as an autofocus in real time, therefore it is possible to measure samples with very high topography without worrying about depth of focus and the sample going in and out of focus no need for additional pass to measure topography or additional hardware, it is all included! A nice added feature Conclusions Tight integration between a SPM system designed for spectroscopy and a powerful micro-spectrometer brings efficient, ultra fast multi-modal imaging to characterize nano materials High spatial resolution and speed is achieved thanks to open access from the top with high NA optics, and lack of interference from the AFM. Lipid layer: and AFM topography 30x30um scan 7um topography Conclusions Suited for TERS with side access port for best polarization and collection efficiency Long term stability insured thanks to rugged, inovative, automated alignment features making it easy to use. Conclusions Experience the most versatile, easy-to-use, and fast simultaneous AFM- system For more information come to our booth # 6 2013 HORIBA, Ltd. All Right Reserved 無断転載 複写複製について本資料の内容の一部あるいは全部を当社の許可なく無断で転載したり変更したりすることは 固くお断りします