A method of forming a relief image in a structure comprising a substrate and a transfer layer formed thereon comprises covering the transfer layer with a polymerizable fluid composition, and then contacting the polymerizable fluid composition with a mold having a relief structure formed therein such that the polymerizable fluid composition fills the relief structure in the mold. The polymerizable fluid composition is subjected to conditions to polymerize polymerizable fluid composition and form a solidified polymeric material therefrom on the transfer layer. The mold is then separated from the solid polymeric material such that a replica of the relief structure in the mold is formed in the solidified polymeric material; and the transfer layer and the solidified polymeric material are subjected to an environment to selectively etch the transfer layer relative to the solidified polymeric material such that a relief image is formed in the transfer layer.

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Step and flash imprint lithography

The present invention is directed to methods for patterning a substrate by imprint lithography. Imprint lithography is a process in which a liquid is dispensed onto a substrate. A template is brought into contact with the liquid and the liquid is cured. The cured liquid includes an imprint of any patterns formed in the template. In one embodiment, the imprint process is designed to imprint only a portion of the substrate. The remainder of the substrate is imprinted by moving the template to a different portion of the template and repeating the imprint lithography process.

Step and repeat imprint lithography processes

Among the various material growth techniques, physical vapor deposition of thin films encompasses many experimental forms. They can be categorized into equilibrium and none-quilibrium processes according to the ways in which the source materials are vaporized. Equilibrium process is typified by thermal evaporation including the conventional resistive heating, the more elaborate e-beam evaporation. as well as molecular beam epitaxy (MBE). Nonequilibrium processes include sputtering and many of its derivative forms such as ion beam deposition. In comparison with these techniques, thin-film deposition by laser evaporation is less well known and does not fall cleanly into either category. Depending on the laserconditions, the evaporation process can be either thermal, nonthermal, or a mixture of the two.

Growth of thin films by laser-induced evaporation

Described are imprint lithography templates, methods of forming and using the templates, and a template holder device. An imprint lithography template may include a body with a plurality of recesses on a surface of the body. The body may be of a material that is substantially transparent to activating light. At least a portion of the plurality of recesses may define features having a feature size less than about 250 nm. A template may be formed by obtaining a material that is substantially transparent to activating light and forming a plurality or recesses on a surface of the template. In some embodiments, a template may further include at least one alignment mark. In some embodiments, a template may further include a gap sensing area. An imprint lithography template may be used to form an imprinted layer in a light curable liquid disposed on a substrate. During use, the template may be disposed within a template holder. The template holder may include a body with an opening configured to receive the template, a support plate, and at least one piezo actuator coupled to the body. The piezo actuator may be configured to alter a physical dimension of the template during use.

Template for room temperature, low pressure micro- and nano-imprint lithography

The present invention is directed to a template having a body including a surface with first and second regions. The first region has first wetting characteristics for a given material and the second region has second wetting characteristics for the given material. The first wetting characteristics differ from the second wetting characteristics. Specifically, the first region is formed from a surface treatment layer with a first surface energy to provide the first wetting characteristics. The second region is exposed portions of the body, typically quartz of fused silica, having a second surface energy associated therewith. The second surface energy is greater than the first surface energy to provide the second region with the second wetting characteristics.

Formation of discontinuous films during an imprint lithography process

Rugate filters are optical thin film interference structures with sinusoidal refractive index profiles. Two-wavelength reflection filters have been fabricated by codeposition of SiO2 and TiO2. Composition modulation was monitored and controlled using quartz crystal rate controllers. The resulting filters exhibited two well-defined stopbands. Microscopic examination revealed that the structure is glasslike without pronounced thin film microstructure.

Codeposition of continuous composition rugate filters.

Sine wave rugate index profiles may be superimposed on a slowly varying average index in such a way as to reduce sidelobes over broad spectral regions and at the same time maintain the strength of the stopband reflectance.

Rugate filter sidelobe suppression using quintic and rugated quintic matching layers.

A method is provided for monitoring and controlling the deposition of multiple layer thin films using a broadband spectral monitor and a generalized model of the film. A design specification, including the number of layers and the material, refractive index, and thickness of each layer, is provided for the desired thin film. A target optical thickness is computed for the end point of each layer using correction factors based on the generalized model, preferably a single layer model, of the multilayer thin film. A monitor chip, such as a silicon substrate, is used for monitoring the multiple layers of film deposition. During deposition of the film, a broadband spectral monitor (BBSM) comprising a source of broadband light is directed onto the monitoring chip. Light reflected by the monitoring chip is received by a photosensor that provides a broadband reflectance spectrum to a computer. The BBSM reflectance spectrum is fit to the generalized model to produce an output corresponding to the optical thickness of the deposited film. When the broadband spectral monitor optical thickness measurement equals the target optical thickness at the end point of the layer, deposition of that layer is terminated and deposition of the next layer may commence. This process is repeated during the deposition of each successive layer until the entire multiple layer thin film is complete.

Deposition of multiple layer thin films using a broadband spectral monitor

A polarizing beamsplitter includes a gradient index film, such as a rugate filter, embedded in an optical medium. The rugate filter is comprises a thin film having a sinusoidal variation in refractive index through its thickness. The embedding medium may include a pair of prisms with the rugate filter between joining faces of the prisms. The rugate filter is embedded so that an incident beam in the embedding medium forms an angle with respect to a normal from the plane of the rugate filter. Embedded at a non-orthogonal angle, the rugate filter is highly transmissive for both the p- and s-polarized broadband components of the incident beam. The beamsplitter is highly reflective, however, at an s-polarization narrow wavelength reflection band determined by the refractive index variations of the rugate filter. Polarizing beamsplitters may be fabricated with multiple reflection bands, including reflection bands in spectral regions other than the visible spectrum. The polarizing beamsplitter can function as a polarizer, a beamsplitter, or a polarizing beamsplitter. An advantage of the invention is efficient reflection of s-polarized light at specific narrow wavelengths with high transmission of s-polarizations at all other wavelengths and p-polarizations at all wavelengths.

Narrow wavelength polarizing beamsplitter

Laser-assisted evaporation of materials has several unique features and is being used increasingly as a thin-film deposition process. Characteristics of this technique and design parameters of a laser-assisted evaporation system are discussed. Types of source material, scanning and focusing of the laser beam, optical elements to deliver laser power to the sources, and emplacement of these elements to deposit thick films are explained.

Randolph L. Hall

Papers

Codeposition of continuous composition rugate filters.

Rugate filter sidelobe suppression using quintic and rugated quintic matching layers.

Deposition of multiple layer thin films using a broadband spectral monitor

Narrow wavelength polarizing beamsplitter

Thin-film deposition by laser-assisted evaporation.