The varied and exotic shapes of new nanoscale organic and inorganic building blocks provide new opportunities to engineer materials possessing specific functionality and physical properties dictated by the unique packings of these particles. We briefly review some of the current strategies for inducing the self-assembly of these building blocks focusing on one strategy in particular—the attachment of tethers to the building blocks at precise locations to create tethered nanoparticle “shape amphiphiles”. We use computer simulation to demonstrate that the resulting anisotropy imparted to nanocrystals or nanocolloids by the tethers can be used to encode simple design rules into the building blocks that ultimately result in a unique self-assembled structure. We present a general classification scheme for tethered nanoparticles wherein the anisotropy of a shape amphiphile is described by a vector comprised of one or more axes each describing a measure of anisotropy.

Self-assembly of anisotropic tethered nanoparticle shape amphiphiles

Step & flash imprint lithography

Motion correction for optical tomographic imaging in three dimensions. An object of interest (1) is illuminated to produce an image (111). A lateral offset correction value is determined for the image (114). An axial offset correction value is determined for the image 115). The lateral offset correction value and the axial offset correction value are applied to the image to produce a corrected file image (116).

Method for correction of relative object-detector motion between successive views

A method is described for acquiring two or more two-dimensional Fourier transforms from different perspectives of a three-dimensional object region (9). A three-dimensional Fourier transform can then be constructed using tomographic methods, permitting the application of image analysis algorithms (52) analogous to those used for two-dimensional images.

Method and apparatus for three-dimensional imaging in the fourier domain

A scanning method for scanning samples of biological cells using optical tomography includes preparing, acquiring, reconstructing and viewing three-dimensional images of cell samples. Concentration and enrichment of the cell sample follows. The cell sample is stained. Cells are isolated from the cell sample and purified. A cell/solvent mixture is injected into a gel by centrifugation. A cell/gel mixture is injected into a capillary tube until a cell appears centered in a field of view using a stopped-flow method. An optical imaging system, such as a fixed or variable motion optical tomography system acquires a projection image. The sample is rotated about a tube axis to generate additional projections. Once image acquisition is completed, the acquired image projections are corrected for errors. A computer or other equivalent processor is used to compute filtered backprojection information for 3D reconstruction.

System and method for processing specimens and images for optical tomography

A method and apparatus for inspection and review of defects is disclosed wherein data gathering is improved. In one embodiment, multiple or segmented detectors are used in a particle beam system.

Method and apparatus for inspecting a substrate

One embodiment disclosed relates to an apparatus for reflection electron beam lithography. An electron source is configured to emit electrons. The electrons are reflected to a target substrate by portions of an electron-opaque patterned structure having a lower voltage level and are absorbed by portions of the structure having a higher voltage level. Another embodiment relates to a novel method of electron beam lithography. An incident electron beam is formed and directed to an opaque patterned structure. Electrons are reflected from portions of the structure having a lower voltage level applied thereto and are absorbed by portions of the structure having a higher voltage level applied thereto. The reflected electrons are directed towards a target substrate to form an image and expose a lithographic pattern.

Maskless reflection electron beam projection lithography

Masks of any next generation lithography (NGL), such as imprint lithography, must eventually achieve and maintain the very low defect counts of current production masks. This requires typically fewer than 10 or even no defects over the entire field. We describe an inspection methodology and how it can be applied to the imprint template. Special test patterns etched onto the template enable both a die to die comparison, to find nuisance defects, and also calibration of sensitivity to different types of preprogrammed defects. A state of the art deep ultraviolet photomask inspection system (KLA-Tencor model 526) can detect these rare events with about 70nm threshold for imprint masks with reflection mode contrast. Initial scans are made at various stages of the imprint process: the newly processed mask, after dicing, and after several imprints. The scans show mostly isolated point defects at a density of ∼10–100permm2. This is an encouraging start for a new NGL, and reductions are expected from better proces...

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Inspection of templates for imprint lithography

One embodiment disclosed relates to an apparatus for detecting defects in substrates. An irradiation source is configured to generate an incident beam, and a lens system configured to focus the incident beam onto a target substrate so as to cause emission of electrons. A multiple-bin detector is configured to detect the emitted electrons, and each bin of the detector detects the emitted electrons within a range of energies. A processing system configured to process signals from the multiple-bin detector. Other embodiments are also disclosed.

Defect detection using energy spectrometer

One embodiment disclosed relates to an electron beam apparatus for inspection of a semiconductor wafer, wherein substantially an entire area of the wafer surface is scanned without moving the stage. A cathode ray tube (CRT) gun may be used to rapidly (and cost effectively) scan the beam over the wafer. Another embodiment disclosed relates to a high-speed automated e-beam inspector configured to scan the e-beam in one dimension while translating the wafer in a perpendicular direction. The translation may be linear, or alternatively, may be in a spiral path. Other embodiments are also disclosed.

Kirk J. Bertsche

Papers

Method and apparatus for inspecting a substrate

Maskless reflection electron beam projection lithography

Inspection of templates for imprint lithography

Defect detection using energy spectrometer

High-speed electron beam inspection