Applejack 199 L.p.

Optoprofiler LLC

Wojciech Jan Walecki

Alexander Pravdivtsev

Mihail Mihaylov

Jae Ryu

Oanh Nguyen

Wei-Chun Hung

Raphael Morency

The invention describes a metrology system allowing for the reduction of the errors caused by vibration of the production floor and allowing for measurements of the thickness of wafers in motion. This is accomplished by performing simultaneous measurements of spectra containing interference signals containing distance information using a plurality of probes positioned on both sides of the measured wafer on the same detector at the same time or by means of plurality of synchronized detectors. System is also able to measure thickness of the individual optically accessible layers present in the sample.

Wafer thickness, topography, and layer thickness metrology system

We describe apparatus for measurement of thickness and topography of slabs of materials employing probes with filters using polarization maintaining fibers.

Measurement of thickness and topography of a slab of materials

The present subject matter includes a method of focusing of an optical imaging apparatus. The method comprises causing illumination of an object using an illuminating beam to thereby cause generation of a scattered beam. A first set of luminous parameters are derived from a first detected position of a luminous representation formed by the scattered beam from the object. The illumination-beam is focused upon the object by triggering a movement of the object along an optical-axis in a first direction, the first direction being based a numerical-representation of the first set of luminous parameters. A second set of luminous parameters are derived from a second detected position of the luminous-representation of the object, the second detected position being related to the first detected position and the movement of the object. The focusing of the illumination beam is ceased based at-least on a numerical-representation of the second set of luminous parameters.

Focusing of optical devices

The present subject matter at least provides an apparatus for inspecting a slab of material including a passivation layer. The apparatus includes a frequency-domain optical-coherence tomography (OCT) probe configured to irradiate the slab of material, and detect radiation reflected from the slab of material. The apparatus also includes a spectral-analysis module configured to analyze at least an interference pattern with respect to the OCT probe to thereby determine a thickness of the slab of the material. The apparatus also includes a thin-film gauge configure to determine a thickness of the passivation layer such that the determined thickness of the slab of material may be adjusted baes on the thickness of the passivation layer.

Multi-probe gauge for slab characterization

A method and apparatus for non-contact measurement of stress in a thin-film deposited on a substrate is disclosed. The method may include positioning a substrate on a plurality of support-elements, the substrate having a thin-film deposited thereupon. A first-polynomial may be defined for representing a surface of the substrate that is in contact with the support elements. A second-polynomial may be determined based on an optimization determination of potential-energy acting upon the substrate. A finite-order polynomial may be created by calculating a product of the first and second polynomials to represent a shape of the surface of the substrate as a model of the surface. Thereafter, stress in the substrate may be determined based on fitting the model of the surface with a measured topographical data of the surface.

Non-contact measurement of a stress in a film on substrate

The present subject matter at least provides an apparatus for characterization of a slab of a material. The apparatus comprises two or more frequency-domain optical-coherence tomography (FD-OCT) probes configured for irradiating the slab of material, and detecting radiation reflected from the slab of material or transmitted there-through. Further, a centralized actuation-mechanism is connected to the OCT probes for simultaneously actuating elements in each of the OCT probes to cause a synchronized detection of the radiation from the slab of material. A spectral-analysis module is provided for analyzing at least an interference pattern with respect to each of the OCT probes to thereby determine at least one of thickness and topography of the slab of the material. Further, in some embodiments, the slab of material may include a passivation layer. The apparatus may be configured to determine a thickness of the passivation layer.

A method for non-contact measurement of stress in a thin-film deposited on a substrate is disclosed. The method may include measuring first topography data of a substrate having a thin-film deposited thereupon. The method may also include comparing the first topography data with second topography data of the substrate that is measured prior to thin-film deposition. The method may further include obtaining a vertical displacement of the substrate based on the comparison between the first topography data and the second topography data. The method may also include detecting a stress value in the thin-film deposited on the substrate based on a fourth-order polynomial equation and the vertical displacement.

Non-contact measurement of a stress in a film on a substrate

Inspecting a multilayer sample may include receiving, at a beam splitter, light and splitting the light into first and second portions; combining, at the beam splitter, the first portion of the light after being reflected from a multilayer sample and the second portion of the light after being reflected from a reflector; receiving, at a computer-controlled system for analyzing Fabry-Perot fringes, the combined light and spectrally analyzing the combined light to determine a value of a total power impinging a slit of the system for analyzing Fabry-Perot fringes; determining an optical path difference (OPD); recording an interferogram that plots the value versus the OPD for the OPD; performing the previous acts of the method one or more additional times with a different OPD; and using the interferogram for each of the different OPDs to determine the thicknesses and order of the layers of the multilayer sample.

Inspecting a multilayer sample

Inspecting a multilayer sample. In one example embodiment, a method may receiving, at a beam splitter, light and splitting the light into first and second portions; combining, at the beam splitter, the first portion of the light after being reflected from a multilayer sample and the second portion of the light after being reflected from a reflector; receiving, at a computer-controlled system for analyzing Fabry-Perot fringes, the combined light and spectrally analyzing the combined light to determine a value of a total power impinging a slit of the system for analyzing Fabry-Perot fringes; determining an optical path difference (OPD); recording an interferogram that plots the value versus the OPD for the OPD; performing the previous acts of the method one or more additional times with a different OPD; and using the interferogram for each of the different OPDs to determine the thicknesses and order of the layers of the multilayer sample.

The present subject matter at-least provides a system for measurement of topography of specular surfaces. The system comprises a set of indexed light-sources and a controller configured to drive the set of light-sources for irradiating a specular-surface by sequentially illuminating a plurality of sub-sets of the light-sources in accordance with a pre-defined encoding criteria. Further, at least one camera is provided to capture reflected light-radiation from the specular-surface and thereby generate a plurality of images in accordance with the sequential-illumination, such that each of the generated-image corresponds to a particular sub-set of illuminated light sources. Further, a processing system is configured to process each generated image in accordance with an image-processing criteria specific to the encoding-criteria to determine one or more index of light-sources and thereby identify the light-sources within the images; and determine topography of the specular-surface at-least based on calculation of spatial-coordinates and the determined identity of each light-source.

Characterization of specular surfaces

Operations related to error reduction in measurement of samples of materials may include operations in which a first distance measurement may be obtained between a first probe and a first surface of a sample at a first time mark. Additionally, the operations may include obtaining a second distance measurement between a second probe and a second surface of the sample at a second time mark. Operations may further include obtaining a third distance measurement between the first probe and the first surface of a sample at a third time mark, and determining a fourth distance measurement between the first probe and the first surface of the sample at the second time mark. In addition, the operations may include determining a thickness of the sample, including an error term due to vibration of the sample. The error term may be discounted from the thickness of the sample.

Error reduction in measurement of samples of materials

According to an aspect of one or more embodiments, the present subject matter describes an apparatus for inspecting a slab of a material. The apparatus comprises a first and second low-coherence sensor configured to irradiate a first and second side of a slab of material with first light having a first polarization and second light having a second polarization, and thereafter configured to detect a reflection. A first polarizer is configured to allow reflected first light having the first polarization to pass through, and reject a second-light cross-talk portion having the second polarization. A second polarizer is configured to allow reflected second light having the second polarization to pass through, and reject a first-light cross-talk portion having the first polarization. Further, a computing-system is configured to receive signals representing the reflected first light and the reflected second light; and analyze the reflected first light and the reflected second light.

Dual-sensor arrangment for inspecting slab of material

The present subject matter at-least provides an apparatus for characterization of a slab of a material. The apparatus comprises a plurality of frequency-domain optical-coherence tomography (FD-OCT) probes configured for irradiating the slab of material at at-least one location, and detecting radiation reflected from the slab of material or transmitted there-through. Further, a centralized actuation-mechanism is connected to the plurality of OCT probes for simultaneously actuating one or more elements in each of said OCT probes to at-least cause a synchronized detection of the radiation from the slab of material. A spectral-analysis module is provided for analyzing at least an interference pattern with respect to each of said OCT probes to thereby determine at least one of thickness and topography of the slab of the material.

Growing community of inventors

Sunrise, FL, United States of America

Wojciech Jan Walecki