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- Brizuela, F., et al.
(author)
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High resolution full-field imaging of nanostructures using compact extreme ultraviolet lasers
- 2009
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In: 9TH INTERNATIONAL CONFERENCE ON X-RAY MICROSCOPY. - : IOP Publishing.
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Conference paper (peer-reviewed)abstract
- Recent advances in the development of high peak brightness table-top extreme ultraviolet (EUV) and soft x-ray (SRX) lasers have opened new opportunities for the demonstration of compact full-field EUV/SXR microscopes capable of capturing images with short exposures down to a single laser shot. We demonstrate the practical application of table-top zone plate EUV microscopes that can image nanostructures with a spatial resolution of 54 nm and below and exposure times as short as 1.2 ns, the duration of a single laser shot.
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- Brizuela, F., et al.
(author)
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Near-wavelength Resolution Extreme Ultraviolet Imaging With a Desktop-size Laser
- 2008
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In: 2008 CONFERENCE ON LASERS AND ELECTRO-OPTICS & QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE, VOLS 1-9. ; , s. 400-401
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Conference paper (peer-reviewed)abstract
- We have realized the first demonstration of imaging in the extreme ultraviolet (EUV) with near-wavelength spatial resolution, 54 nm, using a uniquely compact full-field microscope that can produce images with a single one nanosecond exposure.
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- Menoni, C. S., et al.
(author)
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Advances in Nanoscale Resolution Soft X-Ray Laser Microscopy
- 2009
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In: X-RAY LASERS 2008, PROCEEDINGS. - : Springer Netherlands. - 9781402099236 ; , s. 341-347
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Conference paper (peer-reviewed)abstract
- We review our most recent results on table-top, nanometer-scale resolution, microscopy using compact soft x-ray lasers developed at Colorado State University. We have realized the first demonstration of wavelength-resolution microscopy in the soft x-ray spectral range. Images of carbon nanotubes, 50 nm in diameter, were obtained with a single similar to 1 ns duration laser pulse from a desk-top size capinary discharge 46.9 nm laser. We fully characterized the new microscope by measuring the modulation transfer function of the instrument for zone plate objectives with three different numerical apertures, demonstrating that 54 nm half-period structures can be resolved. The combination of near-wavelength spatial resolution with high temporal resolution imaging opens myriad opportunities for imaging nanoscale structures.
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- Menoni, C. S., et al.
(author)
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Nanometer-scale imaging and ablation with Extreme Ultraviolet lasers
- 2007
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In: 2007 CONFERENCE ON LASERS & ELECTRO-OPTICS/QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2007), VOLS 1-5. - 9781424435906 ; , s. 1401-1402
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Conference paper (peer-reviewed)abstract
- The short wavelength and high brightness of compact extreme ultraviolet lasers is shown to enable the development of microscopes with spatial resolution of tens of nanometers and new types of nanoprobes.
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- Menoni, C. S., et al.
(author)
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Nanoscale resolution microscopy and ablation with extreme ultraviolet lasers
- 2007
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In: 2007 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2. - 9781424409242 ; , s. 488-489
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Conference paper (peer-reviewed)abstract
- We obtain a spatial resolution down to 38 run with full field imaging and laser-ablation systems that exploit the short wavelength and high brightness output from compact extreme ultraviolet lasers in combination with zone plate optics.
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- Rocca, J. J., et al.
(author)
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Compact Soft X-ray Lasers for Imaging, Material Processing, and Characterization at the Nanoscale
- 2007
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In: 32nd IEEE/CPMT International Electronic Manufacturing Technology Symposium. - 9781424413355 ; , s. 72-73
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Conference paper (peer-reviewed)abstract
- As manufacturing of devices advances into the nanoscale, critical feature sizes have rapidly shrunk to below the wavelength of visible light. These advances in nanotechnology have created a need to develop better ways of accessing the nanoworld. The extreme ultraviolet (EUV)/ soft x-ray (SXR) region of the spectrum provides an opportunity to use coherent light at wavelengths that are 10- to 100-times shorter than visible light, at 1 to 100 nm. Given the diffraction limit in imaging resolution, these wavelengths allow us to "see" smaller features and "write" smaller patterns than would be possible with visible light. We have developed compact laser-pumped and discharge-pumped lasers operating at wavelengths of λ=13.2 nm [1] and λ=46.9 nm [2] respectively, and have used them in the demonstration of nanoscale full field imaging [3,4], nanopatterning [5], and nanoscale laser ablation [6]. The high brightness and short wavelength output from these lasers when combined with specialized EUV/SXR optics, offer unique opportunities for the implementation of table-top imaging, patterning and metrology tools with superior spatial resolution for applications in nanoscience and nanotechnology. Using these new compact short wavelength lasers we have built two microscopes, using λ=46.9 nm or λ=l 3.2 nm laser illumination. The compact λ=46.9 nm microscope (Fig. 1a and lb) condenses the light using a multilayer coated Schwarzschild mirror, and images the test object using a diffractive zone plate lens. The spatial resolution of this microscopes was assessed by imaging test samples consisting of dense line gratings of half-periods ranging from 200 down to 35 nm. Figure 2(a) and (b) show images of a 100 nm and 70 nm half-period gratings obtained with the λ =46.9 nm microscope. The lineout in the image of the 70 nm lines shows a modulation of ∼30% indicating that the features are fully resolved according to the Rayleigh criterion. By rearranging the optics, the λ=46.9 nm microscope can also image surfaces. An image of fully resolved dense metal lines, with half-period of 170 nm, patterned on the silicon wafer is shown in Figure 2 (c). The shorter wavelength λ= 3.2 nm microscope uses all zone plate optics to render images of transmissive test patterns with increased spatial resolution . An image of fully resolved 50 nm half-period dense lines acquired with a 20 seconds exposure is shown in Figure 2(d). From images like this one, the spatial resolution of the λ=13.2 nm table-top microscope was determined to be better than 38 nm [3]. The high coherence of these short wavelength lasers also allows for the printing of arrays of nanoscale features using interferometric lithography. We have demonstrated combined a λ=46.9 nm capillary discharge laser and a Lloyd's mirror to print arrays of cone-shaped nano-dots with ∼ 58 nm FWHM diameter (Fig 3a) [5]. The same arrangement was used to print arrays of nano-holes 120 nm FWHM and 100 nm in depth over areas in excess of 500 × 500 μm2 in different photoresists using exposure times as short as 80 s. Larger area patterns can be readily printed using precision translation stages and multiple exposures by overlay superposition. The ability to focus SXL laser light into near diffraction-limited spots also opens the possibility to develop new types of nanoprobes. We have demonstrated ablation of sub-100 nm diameter holes by directly focusing the output of a λ=46.9 nm laser onto a sample with a zone plate lens. Figure 3(b) shows an AFM image of a 82 nm diameter crater obtained ablating a 500 nm thick PMMA layer with a single laser shot. The holes were observed to have very clean walls and high reproducibility. We have recently added the capability to spectroscopically analyze the light emitted from the plasma created during the ablation, opening the possibility to develop analytic nanoprobles. All of these results illustrate the capabilities of compact short wavelength lasers for nanotechnology applications.
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- Brewer, Courtney A., et al.
(author)
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High spatial resolution full-field microscopy using a desktop-size soft x-ray laser
- 2007
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In: Proceedings of SPIE. - : SPIE.
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Conference paper (peer-reviewed)abstract
- Images with nanoscale resolution were obtained in both transmission and reflection modes using a full-field microscope that is illuminated by an extremely compact λ = 46.9 nm (hv = 26.4 eV) soft x-ray laser. The microscope was used to image the surface of partially processed silicon semiconductor chips containing periodic patterns of polysilicon and metal lines. To characterize the microscope, modulation transfer functions were experimentally built for three different objective zone plates, and images with near-wavelength resolution were obtained.
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- Brewer, Courtney A., et al.
(author)
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Single-shot extreme ultraviolet laser imaging of nanostructures with wavelength resolution
- 2008
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In: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 33:5, s. 518-520
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Journal article (peer-reviewed)abstract
- We have demonstrated near-wavelength resolution microscopy in the extreme ultraviolet. Images of 50 nm diameter nanotubes were obtained with a single ~1 ns duration pulse from a desktop-size 46.9 nm laser. We measured the modulation transfer function of the microscope for three different numerical aperture zone plate objectives, demonstrating that 54 nm half-period structures can be resolved. The combination of near-wavelength spatial resolution and high temporal resolution opens myriad opportunities in imaging, such as the ability to directly investigate dynamics of nanoscale structures.
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- Jhavar, Sameer, et al.
(author)
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Integration of ERG gene mapping and gene-expression profiling identifies distinct categories of human prostate cancer
- 2009
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In: BJU International. - 1464-4096. ; 103:9, s. 1256-1269
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Journal article (peer-reviewed)abstract
- OBJECTIVE To integrate the mapping of ERG alterations with the collection of expression microarray (EMA) data, as previous EMA analyses have failed to consider the genetic heterogeneity and complex patterns of ERG alteration frequently found in cancerous prostates. MATERIALS AND METHODS We determined genome-wide expression levels with GeneChip Human Exon 1.0 ST arrays (Affymetrix, Santa Clara, CA, USA) using RNA prepared from 35 specimens of prostate cancer from 28 prostates. RESULTS The expression profiles showed clustering, in unsupervised hierarchical analyses, into two distinct prostate cancer categories, with one group strongly associated with indicators of poor clinical outcome. The two categories are not tightly linked to ERG status. By analysis of the data we identified a subgroup of cancers lacking ERG rearrangements that showed an outlier pattern of SPINK1 mRNA expression. There was a major distinction between ERG rearranged and non-rearranged cancers that involves the levels of expression of genes linked to exposure to beta-oestradiol, and to retinoic acid. CONCLUSIONS Expression profiling of prostate cancer samples containing single patterns of ERG alterations can provide novel insights into the mechanism of prostate cancer development, and support the view that factors other than ERG status are the major determinants of poor clinical outcome.
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