Filmetrics, Inc.

Randall S Geels

Scott A Chalmers

Matthew F Ross

A system comprising a light source, and a retention device configured to receive and retain a sample for measurement. The system includes a detector. An optical path couples light between the light source, the sample when present, and the detector. An optical objective is configured to couple light from the light source to the sample when present, and couple reflected light to the detector. A controller is configured to automatically control focus and/or beam path of the light directed by the optical objective to the sample when present. The system includes a spatially variable filter (SVF) positioned in the optical path. The SVF is configured to have spectral properties that vary as a function of illuminated position on the SVF.

Optical instrumentation including a spatially variable filter

A system comprising a light source configured to illuminate a sample under measurement. The system includes a detector configured to receive reflected light from the sample, and the detector generates a signal representing the reflected light. A spatially variable filter (SVF) is positioned in the optical path. The SVF is configured to have spectral properties that vary as a function of illuminated position on the SVF.

Optical spectrometer configuration including spatially variable filter (SVF)

Embodiments described herein correct errors in spectrometer outputs due to the presence of second-order light. Embodiments determine a relationship between first-order light and second-order light of the spectrometer output. The relationship is a function of wavelength and an output of the spectrometer due to the first-order light. The relationship is used to determine an estimated contribution of the second-order light to the output. Spectrometer errors introduced by the second-order light are corrected by adjusting the spectrometer output according to the estimated contribution of the second-order light.

Correction of second-order diffraction effects in fiber-optic-based spectrometers

Reflectance systems and methods are described that use information of an intermediate reference signal to continuously monitor, detect and/or compensate for drift in a metrology system. The intermediate reference signal is present regardless of whether a sample is being measured. The reflectance system comprises components including a transmission element coupled to a sample area and a receiver. The transmission element is configured to route signals between components of the system. The signals include an illumination signal, and a sample signal resulting from interaction of the illumination signal with a sample when the sample is present in the sample area. The signals also include the reference signal that results from interaction of the illumination signal with one or more components of the system.

Thin-film metrology using spectral reflectance with an intermediate in-line reference

Devices and methods for determining wafer orientation in spectral imaging are described. The devices and methods generate an image of a wafer that includes at least one spectral dimension. One or more properties are determined from the spectral dimension, and a map is generated based on the property. The generated map is compared to at least one other map, and data or information of the comparison is used to locate a region of the wafer, for example a measurement pad or other structure.

Determining wafer orientation in spectral imaging

A system is described that permits high-speed, high-resolution mapping of thicknesses (or other properties) of layers on patterned semiconductor wafers. The system comprises one or more spectrometers that each simultaneously image a plurality of spatial locations. In one example, the spectrometer comprises a two-dimensional CCD imager with one axis of the imager measuring spectral data and the other axis measuring spatial data. Spectral reflectance or transmission of the patterned wafer under test is obtained by passing the wafer under (or over) the imaging spectrometer(s) and taking sequential reflectance or transmission images for successive pluralities of spatial locations. The resulting spectral reflectance or transmission map can then be analyzed at discrete locations to determine the thicknesses or other properties of the layers at those locations.

Method and apparatus for high-speed thickness mapping of patterned thin films

A spectrometer for providing multiple, simultaneous spectra from independent light sources is described characterized in that light from the multiple sources is directed to different portions of a diffraction grating, and the wavelength components of the resultant spectra are directed to at least one receptor.

Spectrometer configured to provide simultaneous multiple intensity spectra from independent light sources

Methods and apparatus for film measurement and endpoint detection in a noisy environment, such as CMP processing of semiconductor wafers, are disclosed, characterized by the use of spectral analysis of intensity data derived from light reflected off the sample to estimate film thickness or detect an endpoint condition.

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San Diego, CA, United States of America

Randall S Geels