Electromagnetic Simulation Optimizes Design of a Sub-20 nm Resolution Optical Microscope

2006 ◽  
Vol 14 (5) ◽  
pp. 28-31
Author(s):  
Erik J. Sanchez
Keyword(s):  
Light Microscopy ◽  
Spatial Resolution ◽  
Near Field ◽  
Optical Microscope ◽  
Diffraction Limit ◽  
Electromagnetic Simulation ◽  
Fundamental Limit ◽  
Scanning Optical Microscopy ◽  
20 Nm ◽  
Near Field Scanning

Recent advances in nanotechnology and nanoscience are highly dependent on our newly acquired ability to measure and manipulate individual structures on the nanoscale. A drawback of light microscopy is the fundamental limit of the attainable spatial resolution dictated by the laws of diffraction at about 250 nanometers. This diffraction limit arises from the fact that it is impossible to focus light to a spot smaller than half its wavelength. The challenge of breaking this limit has led to the development of near-field scanning optical microscopy (NSOM).

Near Field Scanning Optical Microscopy and Spectroscopy of Electronic Materials and Structures

1995 ◽  
Vol 406 ◽  
Author(s):  
W. M. Duncan
Keyword(s):  
Spatial Resolution ◽  
Electronic Materials ◽  
Near Field ◽  
Optical Microscope ◽  
Chemical Information ◽  
Scanning Optical Microscopy ◽  
Thickness Variations ◽  
Physical And Chemical ◽  
Near Field Scanning ◽  
Better Than

AbstractA Near Field Scanning Optical Microscope (NSOM) with spectroscopic capability is applied to imaging semiconductor and microelectronic structures. NSOM combined with spectroscopic analysis provides physical and chemical information of thin films and defects with ultra high spatial resolution. We have studied epitaxial and bulk samples and partially fabricated SiO2/Si CMOS structures to investigate the spatial resolution and imaging modes of NSOM. Reflected intensity contrast in NSOM yields images of defect networks in InGaAs/InAlAs/GaAs epitaxial layers and shows thickness variations in SiO2 films on Si. Surface topological changes observed in NSOM demonstrate a spatial resolution of significantly better than 0.25 μm. Fluorescence imaging is examined for chemically identifying materials and defects.

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

Near-field scanning optical microscopy local luminescence studies of rhodamine dye

Open Physics ◽  
2010 ◽  
Vol 8 (3) ◽  
Author(s):  
Petr Klapetek ◽  
Juraj Bujdák ◽  
Jiří Buršík
Keyword(s):  
Time Domain ◽  
Near Field ◽  
Optical Microscope ◽  
Far Field ◽  
Luminescence Signal ◽  
Local Topography ◽  
Field Radiation ◽  
Scanning Optical Microscopy ◽  
Rhodamine Dye ◽  
Near Field Scanning

AbstractThis article presents results of near-field scanning optical microscope measurement of local luminescence of rhodamine 3B intercalated in montmorillonite samples. We focus on how local topography affects both the excitation and luminescence signals and resulting optical artifacts. The Finite Difference in Time Domain method (FDTD) is used to model the electromagnetic field distribution of the full tip-sample geometry including far-field radiation. Even complex problems like localized luminescence can be simulated computationally using FDTD and these simulations can be used to separate the luminescence signal from topographic artifacts.

Tapping Mode Near-Field Scanning Optical Microscopy of Molecular Crystals and Thin Films

1999 ◽  
Vol 5 (S2) ◽  
pp. 994-995
Author(s):  
C. Daniel Frisbie ◽  
Andrey Kosterin ◽  
Helena Stadniychuk
Keyword(s):  
Optical Microscopy ◽  
Spatial Resolution ◽  
Laser Light ◽  
Near Field ◽  
Sample Surface ◽  
Reflected Light ◽  
Surface Laser ◽  
Scanning Optical Microscopy ◽  
Diffraction Effects ◽  
Near Field Scanning

The diffraction of visible light limits the spatial resolution in conventional optical microscopy to about 200-300 nm. In near-field scanning optical microscopy (NSOM), resolution is improved by bringing the light source, such as the end of an optical fiber, very close to the sample surface. Laser light coupled into the opposite end of the fiber propagates down the fiber core and is emitted from the aperture of the tip. When the sample is in the near-field(roughly within one tip diameter of the end of the tip), the spatial resolution is essentially equal to the diameter of the aperture at the end of the tip and is not determined by diffraction effects. Two-dimensional imaging is accomplished by raster-scanning the sample underneath the fiber tip and collecting transmitted or reflected light at a photodetector.

Near-Field Scanning Optical Microscopy for Through-Silicon Imaging and Fault Isolation of Integrated Circuits

2014 ◽  
Author(s):  
R. Giridharagopal ◽  
T.M. Eiles ◽  
B. Niu
Keyword(s):  
Optical Microscopy ◽  
Integrated Circuit ◽  
Near Field ◽  
Diffraction Limit ◽  
Fault Isolation ◽  
Lateral Resolution ◽  
Excitation Wavelength ◽  
Process Technology ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

Abstract We present the first known images acquired using near-field scanning optical microscopy (NSOM) through backside silicon on functional integrated circuit samples with higher resolution than conventional fault isolation (FI) tools. NSOM offers the possibility of substantially-improved lateral resolution independent of excitation wavelength. Current FI techniques have challenged the resolution limits of conventional optics technology, even in the best solid immersion lens (SIL) to date. This poses a problem for future process technology nodes. This resolution barrier is a by-product of the diffraction limit. In Fourier terms, a conventional lens filters out highfrequency information and thus limits the resolution. In NSOM, by placing a tip with an aperture in extreme proximity to the surface it is possible to capture the near-field light that contains high-frequency information, thereby circumventing the diffraction limit. The tangible benefit is that the resolution is substantially improved. We show that NSOM can be used in backside subsurface imaging of silicon, mirroring the paradigm used in typical optical FI. We present optical reflectance data through ~100 nm of remaining backside Si on functional 22 nm CMOS IC parts with lateral resolution approaching 100 nm. We then discuss potential methods for using NSOM in practical backside fault isolation applications and for improving signal-to-noise ratio (SNR).

Measurement of Strain Associated with Defects in SiTiO3 Bicrystals using Near-Field Scanning Optical Microscopy

1997 ◽  
Vol 474 ◽  
Author(s):  
E. B. McDaniel ◽  
J. W. P. Hsu
Keyword(s):  
Optical Microscopy ◽  
Near Field ◽  
Optical Microscope ◽  
Nanometer Scale ◽  
Polarization Modulation ◽  
Reflection Symmetry ◽  
Strain Fields ◽  
Modulation Technique ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

ABSTRACTWe incorporate a polarization modulation technique in a near-field scanning optical microscope (NSOM) for quantitative polarimetry studies at the nanometer scale. Using this technique, we map out stress-induced birefringence associated with submicron defects at the fusion boundaries of SiTiO3 bicrystals. The strain fields surrounding these defects are larger than the defect sizes and show complex spiral shapes that break the reflection symmetry of the bicrystal boundary.

Photoreflectance Near-Field Scanning Optical Microscopy

1999 ◽  
Vol 588 ◽  
Author(s):  
Charles Paulson ◽  
Brian Hawkins ◽  
Jingxi Sun ◽  
Arthur B. Ellis ◽  
Leon Mccaughan ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Electric Fields ◽  
Spatial Resolution ◽  
High Intensity ◽  
Near Field ◽  
And Topology ◽  
Wavelength Resolution ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning ◽  
Sub Wavelength

AbstractA novel Near-field Scanning Optical Microscopy (NSOM) technique is used to obtain simultaneous topology, photoluminescence and photoreflectance (PR) spectra. PR spectra from GaAs surfaces were obtained and the local electric fields were calculated. Sub-wavelength resolution is expected for this technique and achieved for PL and topology measurements. Photovoltages, resulting from the high intensity of light at the NSOM tip, can limit the spatial resolution of the electric field determination.

Progress in near-field scanning optical microscopy (NSOM)

1988 ◽  
Vol 46 ◽  
pp. 436-437
Author(s):  
E. Betzig ◽  
M. Isaacson ◽  
H. Barshatzky ◽  
K. Lin ◽  
A. Lewis
Keyword(s):  
Optical Microscopy ◽  
Near Field ◽  
Visible Region ◽  
Optical Microscope ◽  
Scanning Tunneling ◽  
Far Field ◽  
Tunneling Microscopy ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning ◽  
Scanning Electron

The concept of near field scanning optical microscopy was first described more than thirty years ago1 almost two decades before the validity of the technique was verified experimentally for electromagnetic radiation of 3cm wavelength.2 The extension of the method to the visible region of the spectrum took another decade since it required the development of micropositioning and aperture fabrication on a scale five orders of magnitude smaller than that used for the microwave experiments. Since initial reports on near field optical imaging8-6, there has been a growing effort by ourselves6 and other groups7 to extend the technology and develop the near field scanning optical microscope (NSOM) into a useful tool to complement conventional (i.e., far field) scanning optical microscopy (SOM), scanning electron microscopy (SEM) and scanning tunneling microscopy. In the context of this symposium on “Microscopy Without Lenses”, NSOM can be thought of as an addition to the exploding field of scanned tip microscopy although we did not originally conceive it as such.

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