Abstract: The present invention is directed to a self referencing heterodyne reflectometer system and method for obtaining highly accurate phase shift information from heterodyned optical signals, without the availability of a reference wafer for calibrations. The self referencing heterodyne reflectometer rapidly alternates between a heterodyne reflectometry (HR) mode, in which an HR beam comprised of s- and p-polarized beam components at split angular frequencies of ? and ?+?? is employed, and a self referencing (SR) mode, in which an SR beam comprised of p-polarized beam components at split angular frequencies of ? and ?+?? is employed. When the two measurements are made in rapid succession, temperature induced noise in the detector is be assumed to be the same as for both measurements. A measured phase shift ?Ref/film is generated from the HR beam and a reference phase shift ?Ref/Sub is generated from the SR beam.

Abstract: 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.

Abstract: A linearly polarized light comprised of two linearly polarized components, orthogonal to each other and with split optical frequencies, is directed toward a film. A detector receives the beam prior to incidence on the film layer and generates a reference signal. The reflected beam is diffracted into zeroth- and first-order bands, which are then detected by separate detectors; a measurement signal is generated from the zeroth-order beam and a grating signal from the first-order beam. The zeroth-order beam's measurement signal and reference signal are analyzed by a phase detector for a heterodyne phase shift, and an accurate film thickness calculated from this phase shift by knowing a refractive index for the film. Additionally, the zeroth-order beam measurement signal is analyzed with the grating signal by a phase detector for detecting a grating phase shift induced by the grating.

Abstract: 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.

Abstract: An optical profilometer apparatus 10 having a stage with a support surface 42 on which a wafer substrate may rest. The wafer stage is capable of moving the wafer in (x, y) or (r, ?) mode to achieve complete wafer scan. Polarized light from a monochromatic source 12 is directed towards the wafer surface 22. Surface profiling is achieved by sensing beam shift on a segmented sensor caused by level/height change at the wafer surface. In preferred embodiment of the profilometer, a single light beam is engineered to propagate in two orthogonal planes of incidence so that it becomes sensitive to height/level change on the wafer while being insensitive to local slope or wafer tilt. In another embodiment, slope of surface feature is measured. By integrating slope over the measurement spot, local feature height is obtained. This is particularly useful when the beam shift due to feature height change is below detection sensitivity.

Abstract: 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.

Abstract: 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.

Abstract: Afterglow spectroscopy allows observing light emission of gaseous species in absence of direct plasma light. This absence avoids the creation of a background spectrum obscuring weak emission from trace species. The invention describes a flowing afterglow version monitoring in-situ the cleanup of vacuum tools during pump/purge cycles. The invention also describes an intermittent afterglow version suitable for trace gas analysis at atmospheric pressure.

Abstract: The present invention is directed to a system, method and software product for creating a predictive model of the endpoint of etch processes using Partial Least Squares Discriminant Analysis (PLS-DA). Calibration data is collected from a calibration wafer using optical emission spectroscopy (OES). The data may be non-periodic or periodic with time and periodic signals may be sampled synchronously or non-synchronously. The OES data is arranged in a spectra matrix X having one row for each data sample. The OES data is processed depending upon whether or not it is synchronous. Synchronous data is arranged in an unfolded spectra matrix X having one row for each period of data samples. A previewed endpoint signal is plotted using wavelengths known to exhibit good endpoint characteristics. Regions of stable intensity values in the endpoint plot that are associated with either the etch region or the post-etch region are identified by sample number.

Abstract: 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.

Abstract: 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.

Abstract: The power supply may be operated during a given cycle sequentially to produce high and low frequency drive signals for operating an ultrasonic transducer for sequentially producing an ultrasonic output at the two frequencies to carry out bonding operations at two different bond sites respectively.

Abstract: The power supply includes a voltage controlled oscillator, two potentiometers and a by-pass circuit coupled to the output of the voltage controlled oscillator. The two potentiometers form two channels, channel 1 and channel 2, one of which will be selected during the bonding cycle to be coupled to a power amplifier. The output of the power amplifier is adapted to be coupled to an ultrasonic transducer for operating the transducer. Selectable channel 1 and channel 2 reference voltage devices are provided. The voltage and current applied to the amplifier are converted to power. During a bonding cycle, a comparator compares the power applied to the transducer with that of a selected reference voltage and varies the output of the potentiometer of the selected channel to maintain the output of the power amplifier constant during bonding.

Abstract: The transducer has a metal body with a welding end, an opposite end for supporting a source for causing the body and the welding end to vibrate at ultrasonic frequency for welding purposes and an intermediate mounting structure for supporting the body for welding purpose. The mounting structure may be a cylinder or flange spaced from and surrounding the body with at least two spaced apart spokes connected between the body and the mounting structure.