Abstract: Reflectance systems and methods are described that under-fill the collection fiber of a host spectrometer both spatially and angularly. The under-filled collection fiber produces a response of fiber-based spectrometers that is relatively insensitive to sample shape and position.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Spectral imaging systems and methods are provided for monitoring a substrate during a chemical-mechanical planarization process. An example system includes a carrier configured to receive a substrate, and a platen configured to receive a polishing pad. The platen includes an aperture configured to pass light. The system also includes a frame that disposes the platen in any number of positions relative to the carrier. An optoelectronic system is coupled to the aperture, and the aperture passes light of the optoelectronic system to illuminate the substrate and passes reflected light from the substrate to the optoelectronic system. A processing system is coupled to the optoelectronic system and uses the reflected light to image the substrate as the polishing pad is polishing the substrate.

Abstract: 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.

Abstract: An apparatus or method captures reflectance spectrum for each of a plurality of spatial locations on the surface of a patterned wafer. A spectrometer system having a wavelength-dispersive element receives light reflected from the locations and separates the light into its constituent wavelength components. A one-dimensional imager scans the reflected light during translation of the wafer with respect to the spectrometer to obtain a set of successive, spatially contiguous, one-spatial dimension spectral images. A processor aggregates the images to form a two-spatial dimension spectral image. One or more properties of the wafer, such as film thickness, are determined from the spectral image. The apparatus or method may provide for relatively translating the wafer at a desired angle with respect to the line being imaged by the spectrometer to enhance measurement spot density, and may provide for automatic focusing of the wafer image by displacement sensor feedback control.

Abstract: An apparatus or method captures reflectance spectrum for each of a plurality of spatial locations on the surface of a patterned wafer. A spectrometer system having a wavelength-dispersive element receives light reflected from the locations and separates the light into its constituent wavelength components. A one-dimensional imager scans the reflected light during translation of the wafer with respect to the spectrometer to obtain a set of successive, spatially contiguous, one-spatial dimension spectral images. A processor aggregates the images to form a two-spatial dimension spectral image. One or more properties of the wafer, such as film thickness, are determined from the spectral image. The apparatus or method may generate a wavelength-dependent correction factor to correct for diffraction errors introduced in reflectance spectra by the wavelength-dispersive element. The invention provides for automatic rotation of a patterned wafer to determine Goodness of Alignment during a measurement process.

Abstract: Systems of and methods for capturing a plurality of one-dimensional images representative of substantially all of the surface of a substrate within a single revolution of a rotating platen holding a polishing pad in operative contact with the surface of the substrate during chemical-mechanical planarization. A two-dimensional image comprising frame data, which may comprise a spectral image, is derived from the plurality of one-dimensional images. The frame data provides information useful for subsequent chemical-mechanical processing of the substrate.

Abstract: 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.

Abstract: Methods and apparatus for measuring the thickness of at least one individual film added to, removed from, or within a sample, characterized by the use of a shift in a selected peak of thickness spectral data to estimate the thickness of the individual film.

Abstract: 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.

Abstract: 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.

Abstract: We report a method for accurate growth of vertical-cavity surface-emitting lasers (VCSELs). The method uses a single reflectivity spectrum measurement to determine the structure of the partially completed VCSEL at a critical point of growth. This information, along with the extracted growth rates, allows imprecisions in growth parameters to be compensated for during growth of the remaining structure, which can then be completed with very accurate critical dimensions. Using this method, we can now routinely grow lasing VCSELs with Fabry-Perot cavity resonance wavelengths controlled to within 0.5%.

Abstract: A method is described for reproducibly controlling layer thickness and varying layer composition in an MBE deposition process. In particular, the present invention includes epitaxially depositing a plurality of layers of material on a substrate with a plurality of growth cycles whereby the average of the instantaneous growth rates for each growth cycle and from one growth cycle to the next remains substantially constant as a function of time.

Abstract: An ultragrating is a nanometer-period optical grating that is fabricated from a horizontal superlattice. A superlattice is a material structure grown on a substrate by molecular-beam epitaxy or metal-organic chemical vapor deposition and having periodic compositional variations. A horizontal superlattice is one in which the compositional variations are in a direction parallel to the substrate surface. By the selective removal of one of the superlattice materials, an ultragrating is obtained. The smallest grating periods possible before this discovery were those made by electron-beam lithographic techniques which are limited to values greater than 100 nanometers. Thus, the ultragrating with grating periods ranging from one to a hundred nanometers represents an order of magnitude advancement in the state of the art of making optical gratings. The ultragrating will fine utility in the design of advanced electronic devices and for general scientific and engineering purposes.