California Institute of Technology

Ultratech, Inc.

Ares J Rosakis

Yonggang Huang

Subra Suresh

David M Owen

Michael Mello

David A Boyd

Sean Olson

Elizabeth Kolawa

Ilan Blech

Antonios Giannakopoulos

Nicholas R Moore, Jr

Alan T Zehnder

Stephen Gledden

G Ravichandran

Ramen P Singh

Apparatus, techniques and systems for implementing an optical interferometer to measure surfaces, including mapping of instantaneous curvature or in-plane and out-of-plane displacement field gradients of a sample surface based on obtaining and processing four optical interferograms from a common optical reflected beam from the sample surface that are relatively separated in phase by &#x3c0;/2.

Surface characterization based on optical phase shifting interferometry

Techniques and devices are described to use spatially-varying curvature information of a layered structure to determine stresses at each location with non-local contributions from other locations of the structure. For example, a local contribution to stresses at a selected location on a layered structure formed on a substrate is determined from curvature changes at the selected location and a non-local contribution to the stresses at the selected location is also determined from curvature changes at all locations across the layered structure. Next, the local contribution and the non-local contribution are combined to determine the total stresses at the selected location.

Characterizing curvatures and stresses in thin-film structures on substrates having spatially non-uniform variations

Systems are described that include computer program products that enable data processing apparatus to perform operations to determine stresses for a system including a substrate with a plurality of films layered thereon. The operations include determining film stresses and system curvatures in terms of misfit strains and thicknesses the plurality of films, determining film stresses and interface shear stresses in terms of system curvature and the thicknesses of each film, and transmitting the film stresses and the interface shear stresses to a computer-readable medium.

Measuring stresses in multi-layer thin film systems with variable film thickness

Apparatus and techniques for using an optical shearing interferometry to obtain full field mapping of in-plane and out-of-plane displacement field gradients of a sample surface of a sample.

Surface characterization based on lateral shearing of diffracted wave fronts to measure in-plane and out-of-plane displacement gradient fields

Techniques and devices are described to use spatially-varying curvature information of a layered structure to determine stresses at each location with non-local contributions from other locations of the structure. For example, a local contribution to stresses at a selected location on a layered structure formed on a substrate is determined from curvature changes at the selected location and a non-local contribution to the stresses at the selected location is also determined from curvature changes at all locations across the layered structure. Next, the local contribution and the non-local contribution are combined to determine the total stresses at the selected location. Techniques and devices for determining a misfit strain between a film and a substrate on which the film is deposited are also described.

Techniques and devices for characterizing spatially non-uniform curvatures and stresses in thin-film structures on substrates with non-local effects

Techniques and systems for using optical interferometers to obtain full-field optical measurements of surfaces, such as surfaces of flat panels, patterned surfaces of wafers and substrates. Applications of various shearing interferometers for measuring surfaces are described.

Full-field optical measurements of surface properties of panels, substrates and wafers

Techniques for analyzing non-uniform curvatures and stresses in thin-film structures on substrates with non-local effects

Methods and systems for evaluating stresses in line features formed on substrates. Stresses may be computed from measured curvature information based on simple analytical functions. The curvature information can be obtained optically by, e.g., a coherent gradient sensing method, to obtain a full-field measurement of an illuminated area.

Systems for measuring stresses in line features formed on substrates

Techniques for determining large deformation of layered or graded structures to include effects of body forces such as gravity, electrostatic or electromagnetic forces, and other forces that uniformly distribute over the structures, support forces, and concentrated forces. A real-time stress monitoring system is also disclosed to provide in-situ monitoring of a device based on the large deformation analytical approach. A coherent gradient sensing module, for example, may be included in such a system.

Determining large deformations and stresses of layered and graded structures to include effects of body forces

Real-time evaluation of stress fields and properties in line features formed on substrates

Systems and techniques for integrating an optical coherent gradient sensing (CGS) module and another optical sensing module to simultaneously measure the curvature and another property of a specularly reflective surface.

Coherent gradient sensing ellipsometer

A system and method for radiation detection with an increased frame rate. A semi-parallel processing configuration is used to process a row or column of pixels in a focal-plane array in parallel to achieve a processing rate up to and greater than 1 million frames per second.

High speed infrared imaging system and method

A system and method for determining a curvature of a specularly reflective surface based on optical interference. Two optical gratings are used to produce a spatial displacement in an interference field of two different diffraction components produced by one grating from different diffraction components produced by another grating. Thus, the curvature of the surface can be determined.

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Altadena, CA, United States of America

Ares J Rosakis