Verity Instruments, Inc.

Other

The University of Texas System

Lam Research Corporation

Andrew Weeks Kueny

Mike Whelan

Mark Anthony Meloni

John D Corless

Kenneth C Harvey

Randall S Mundt

Albert J Lamm

Arun Ananth Aiyer

David U Fluckiger

Matthew J Goeckner

Jimmy W Hosch

Sean Lynes

Chris D Pylant

Rick Daignault

Pl Stephan Thamban

The disclosure provides features for improved processing of optical data by identifying and characterizing stationary and transient signals in the electrical data representing the data collected from an optical sensor of an optical measurement system. In one example, an optical measurement system is disclosed that includes: (1) a pixel area of an optical sensor having multiple pixels that store an electrical charge corresponding to a received optical signal, (2) one or more reduced illumination regions that provide signal levels intrinsic to the optical sensor, and (3) one or more processors configured to adjust, during active operation of the system, digital representations of the electrical charges from the pixels of the pixel area using characterizations of the signal levels from the one or more reduced illumination regions.

System, apparatus, and method for improved background correction and calibration of optical devices

A system and method of use for simplifying the measurement of various properties of complex semiconductor structures is provided. The system and method supports reduction of structure complexity and modeling for optical monitoring and permits determination of film thicknesses and feature depths during semiconductor manufacturing processes.

System and method for measurement of complex structures

The disclosure provides an optical calibration device for in-chamber calibration of optical signals associated with a processing chamber, a characterization system for plasma processing chambers, methods of characterizing plasma processing chambers, and a chamber characterizer. In one example, the optical calibration device includes: (1) an enclosure, (2) an optical source located within the enclosure and configured to provide a source light having a continuous spectrum, and (3) optical shaping elements located within the enclosure and configured to form the source light into a calibrating light that approximates a plasma emission during an operation within the processing chamber.

System and method for calibration of optical signals in semiconductor process systems

The present invention is directed to a gas line electron beam exciter, gas line electron beam excitation system and method for exciting a gas using an electron beam exciter. The electron beam exciter generally comprises a variable density electron source for generating a cloud of electrons in an electron chamber and a variable energy electron extractor for accelerating electrons from the electron chamber as an electron beam and into an effluent stream for fluorescing species in the effluent. The electron density of the electron beam is variably controlled by adjusting the excitation power applied to the variable density electron source. The electrons in the electron chamber reside at a reference electrical potential of the chamber, typically near ground electrical potential. The electron energy of the electron beam is variably controlled by adjusting an electrical potential across the variable energy electron extractor, which energizes the electrons through an extraction hole of the chamber and toward the extractor. The greater the difference in the electrical potential between the electron extractor and the electron source, the higher the energy imparted to the electrons in the electron beam. The excitation power applied to the electron source can be adjusted independently from the electron energy of the electron beam, thereby altering the electron density of the electron beam without changing the energy level of the electrons of the electron beam.

Electron beam exciter for use in chemical analysis in processing systems

A referenced and stabilized optical measurement system includes a light source, a plurality of optical elements and optical fiber assemblies and a detector arranged to compensate for the effects of system variation which may affect measurement performance. A non-continuous light source provides a common source light on a common source path. A reference light and a measurement light are derived from the common source light and propagated across separate paths of optically matching optical components in order to produce a common signal variation on both the reference light signal and the measurement light signal. Light paths exposed to air are contained indiscrete volumes for purging gasses from the volumes. Ratios of the reference signal and measurement signal are acquired under various conditions for compensating the measurement signal for system variations.

Referenced and stabilized optical measurement system

The present invention is directed to an apparatus, method and software product for enhancing the dynamic range of a CCD sensor without substantially increasing the noise. Initially, the area of a N&#xd7;M pixel CCD sensor array is subdivided into two regions, a large region having (M&#x2212;a) pixels in each column for outputting large-amplitude signals with low noise and a smaller region having a pixels in each column for outputting small-amplitude signals with improved dynamic range. At integration time, the CCD is read out one region's rows at a time into the horizontal shift registers by shifting the pixel charges in either a or M&#x2212;a vertical shifts. The charges in the horizontal shift registers are then shifted out of the horizontal shift registers in N horizontal shifts. Next, the remaining pixels in the region of the CCD are read out into the horizontal shift registers by shifting the pixel charges in the other of a or M&#x2212;a vertical shifts. Those charges are then shifted out of the horizontal shift registers in N horizontal shifts. In a spectrographic application, the data from the two regions is read out in the form of a large-amplitude channel from the larger region's rows and a small-amplitude channel from the smaller region's rows.

Apparatus and method for enhancing dynamic range of charge coupled device-based spectrograph

A workpiece characterization system for obtaining simultaneous measurement of layer and photoluminescence properties of a workpiece. The workpiece characterization system includes an excitation light and an illumination light each impinging upon a surface of a workpiece whereby the workpiece emits photoluminescent light and encodes light from said illumination source with layer information. The excitation light and the illumination light are generated from a single light source. The light from the single light source is filtered to remove wavelengths of light that correlate to light wavelengths emitted from the workpiece as a result of excitation. Wavelengths that correlate to light reflected from the workpiece that may contain encoded information are not filtered.

Workpiece characterization system

The present invention is directed to a system and method for radiometric calibration of spectroscopy equipment utilized in fault detection and process monitoring. Initially, a reference spectrograph is calibrated to a local primary standard (a calibrated light source with known spectral intensities and traceable to a reference standard). Other spectrographs are then calibrated from the reference spectrograph rather than the local primary calibration standard. This is accomplished by viewing a light source with both the reference spectrograph and the spectrograph to be calibrated. The output from the spectrograph to be calibrated is compared to the output of the reference spectrograph and then adjusted to match that output. The present calibration process can be performed in two stages, the first with the spectrographs calibrated to the reference spectrograph and then are fine tuned to a narrow band light source at the plasma chamber. Alternatively, the reference spectrograph can be calibrated to the local primary standard while optically coupled to the plasma chamber. There, the local primary standard calibration light source is temporarily positioned within the plasma chamber, or in a light chamber disposed along the interior of the chamber for calibrating the reference spectrograph. Other spectrographs can be calibrated to the reference spectrograph while coupled to the plasma chamber with the local primary standard calibration light source, thereby calibrating every component in the entire optical path to the reference spectrograph.

Calibration of a radiometric optical monitoring system used for fault detection and process monitoring

The present invention is directed to a heterodyne reflectometer system and method for obtaining highly accurate phase shift information from heterodyned optical signals, from which extremely accurate film depths can be calculated. A linearly polarized light comprised of two linearly polarized components that are orthogonal to each other, with split optical frequencies, is directed toward a film causing one of the optical polarization components to lag behind the other due to an increase in the optical path in the film for that component. A pair of detectors receives the beam reflected from the film layer and produces a measurement signal, and the beam prior to incidence on the film layer and generates a reference signal, respectively. The measurement signal and reference signal are analyzed by a phase detector for phase shift. The detected phase shift is then fed into a thickness calculator for film thickness results. A grating interferometer may be included with the heterodyne reflectometer system with a grating, which diffracts the reflected beam into zeroth- and first-order bands, which are then detected by separate detectors. A detector receives the zeroth-order beam and generates another measurement signal. Another detector receives the first-order beam and generates a grating signal. The measurement signal from the grating and reference signal may be analyzed by a phase detector for phase shift, which is related to the thickness of the film. Conversely, either measurement signal may be analyzed with the grating signal by a phase detector for detecting a grating phase shift. The refractive index for the film may be calculated from grating phase shift and the heterodyne phase shift. The updated refractive index is then used for calculating thickness.

Heterodyne reflectometer for film thickness monitoring and method for implementing

The present invention is directed to a system, method and software program product for calculating metrological data (e.g. layer thicknesses and depths of recesses and trenches) on a surface or structure, such as a semiconductor wafer. The present method does not require knowledge of the reflectivity or transmissivity of the surface or structure, but only a quantity related to the reflectivity or transmissivity linear transformation needs to be known. Initially, a simplified optical model for the process is constructed using as many parameters as necessary for calculating the surface reflectivity of the discrete regions on the wafer. Reflectivity data are collected from the surface of a wafer using, for instance, in-situ monitoring, and nominal reflectivity is determined from the ratio of the current spectrum to a reference spectrum. The reference spectrum is taken from a reference wafer consisting entirely of a material in which the reflection properties are well characterized. Both the observed and calculated data are transformed such that their vertical extents and spectrally averaged values coincide. By transforming both the observed data and calculated model such that their vertical extents and spectrally averaged values coincide, large errors in both the data and the model can be tolerated. A merit function is employed which measures the agreement between observed data and the model with a particular choice of parameters. The merit function may be minimized using a standard numerical technique for finding a deep minimum in the merit function at the correct values of the parameters.

System and method for in-situ monitor and control of film thickness and trench depth

For use with a chemical mechanical polishing apparatus for polishing a semiconductor wafer having a platen, a polishing pad and a wafer carrier, an optical closed-loop control system. In one embodiment, the system includes a plurality of optical probes impacting a corresponding probe window and rigidly mountable through the platen. The system also includes a flash lamp configured to provide light to each of the plurality of optical probes and minimize an exposure time of the light onto the semiconductor wafer, a spectrograph configured to spatially image light received by each of the plurality of optical probes to a common charge-coupled device and produce real-time spectral reflectometry data therefrom. The system further includes a control subsystem configured to analyze the real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause the polishing to be adjusted based upon the at least one wafer state parameter.

Optical closed-loop control system for a CMP apparatus and method of manufacture thereof

Apparatus characterizes the quality of microelectronic features using broadband white light. A highly collimated light source illuminates an area of a first wafer using broadband multi-spectral light. The angular distribution of the light scattered from the first wafer is then measured. Generally, the angle of the light source, detector, or both is altered and an angular distribution measurement taken at each angle, producing a scatter signature for the first wafer. Finally, the scatter signature of the first wafer is compared with a known scatter signature of a second wafer of good quality to determine the quality of the first wafer.

Apparatus for characterization of microelectronic feature quality

Disclosed is a method for characterizing the quality of microelectronic features using broadband white light. A highly collimated light source illuminates an area of a first wafer using broadband multi-spectral light. The angular distribution of the light scattered from the first wafer is then measured. Generally, the angle of the light source, detector, or both is altered and an angular distribution measurement taken at each angle, producing a scatter signature for the first wafer. Finally, the scatter signature of the first wafer is compared with a known scatter signature of a second wafer of good quality to determine the quality of the first wafer.

Method for characterization of microelectronic feature quality

A spectral ellipsometer that enables complete simultaneous measurement of ellipsometric parameters of a surface with thin films and coatings for the full wavelength range of interest by using an imaging spectrograph together with a novel optical arrangement that disperses the polarization information of a time-invariant train of optical signals in a linear spatial array of points along or parallel to an input aperture or slit of the imaging spectrograph and disperses the polarization information in wavelength perpendicular to the aperture or slit to provide a two-dimensional spectrograph image that is collected and stored by an imaging array with one axis relating to wavelength and the other axis relating to the light polarization. Multiple simultaneous measurements of the spectral ellipsometric parameters .psi. (psi) and .DELTA. (delta) are taken at all wavelengths without the need of any time-varying or mechanically-moving optical elements. The ellipsometer can be used for real-time measurements of ellipsometric parameters of a moving or static surface with the thin films and coatings.

Growing community of inventors

Dallas, TX, United States of America

Andrew Weeks Kueny