Method of measuring dishing using relative height measurements
Granted: March 2, 2004
Patent Number:
6700670
A metrology process, in accordance with the present invention, measures the dishing of a feature, such as a copper, aluminum, or tungsten metal line, with respect to another feature, such as a dielectric layer, that surround the first feature by measuring the relative heights of varying line widths of the first feature with respect to the second feature. The relative heights are adjusted to correspond to the actual dishing value using a calibration point of a calibration line width and a…
Alignment of a rotatable polarizer with a sample
Granted: December 16, 2003
Patent Number:
6665070
A metrology device with a rotatable polarizer is calibrated to align the transmission axis of the polarizer with the axis of orientation of a sample, such as a diffraction grating. The axis of orientation of the diffraction grating can be either the TE or TM axis. The system offset angle between the transmission axis of the polarizer in its home position and an axis of motion of the stage, such as a polar coordinate stage, is determined. Whenever a new substrate is loaded onto the stage,…
Dual spot confocal displacement sensor
Granted: December 2, 2003
Patent Number:
6657216
A confocal displacement sensor uses one or two light sources and produces two spots on a sample surface. The reflected intensities from the two spots are detected and measured by one or two detectors. A vertical resolution enhancement can be implemented by modifying the properties of the objective and/or detector lenses. The resultant height profile does not need to be corrected for tilt as is common with all single point surface measurement techniques. A differential scan can be…
Profiling method
Granted: October 14, 2003
Patent Number:
6633389
A profiling method compensates for phase changes associated with the presence of multiple or varying material in the area to be measured. The profiling method measures at least a portion of the height profile of the area of interest. The phase of the different materials in the region are also obtained and used to generate a correction factor. Depending on the type of material in the region of interest, the correction factor may be the material specific phase difference of the materials…
Surface profiling using a differential interferometer
Granted: June 17, 2003
Patent Number:
6580515
A differential interferometer is used to measure the step height between a reference region and at least one point in a measurement region using the relative phase difference as well as the measured reflectance from at least the point in the measurement region. The measured reflectance can be derived from the information provided by the differential interferometer. The measured reflectance from the reference region can also be used to provide a step height measured, where, e.g., the…
Film thickness measurements using light absorption
Granted: June 3, 2003
Patent Number:
6573999
A method of measuring film thickness is based on the film's attenuation of optical characteristics, such as absorption band or absorption bands, of underlying material. The thickness of the film is determined based on a correlation between the thickness of the film and the strength of the absorption band (such as a peak or valley area) of the underlying material. The correlation is generated using an identified absorption band of the underlying material, which may be determined…
Method of measuring dishing using relative height measurement
Granted: May 27, 2003
Patent Number:
6568290
A metrology process, in accordance with the present invention, measures the dishing of a first feature made of a first material by determining the relative height of the first feature with respect to a second feature, where the first and second features have different dishing rates. The relative height of the first feature with respect to the second feature may be determined by measuring a first relative height of the first feature with respect to a reference location, measuring a second…
Correcting the system polarization sensitivity of a metrology tool having a rotatable polarizer
Granted: February 18, 2003
Patent Number:
6522406
The calibration of a metrology tool with a rotatable polarizer separates the angular dependence of the irradiance from the temporal dependence. The angular dependence of the metrology tool is then modeled, e.g. using a Fourier expansion. The Fourier coefficients are parameterized as a function of wavelength. The actual irradiance, e.g., the reference irradiance and/or back reflection irradiance, is then measured for the metrology tool for one angle of the rotatable polarizer. From the…
Edge gripped substrate loading and unloading method
Granted: November 26, 2002
Patent Number:
6485253
A substrate lift mechanism includes a plurality of fingers mounted on a hoop controlled by an actuator to transfer a substrate, such as a wafer or a flat panel display, from an edge grip arm to a chuck on a processing tool, such as integrated metrology tools. The substrate lift mechanism includes a base that is configured to be mounted to existing processing tools thereby allowing the processing tools to be adapted to be operable with new edge grip arms. The plurality of fingers are…
Elemental concentration measuring methods and instruments
Granted: April 30, 2002
Patent Number:
6381009
An instrument and methods are used to determine film layer thicknesses, optical constant spectra, and elemental concentrations of a sample substrate overlaid with a single or multiple films. The instrument measures the sample substrate's absolute reflectance and ellipsometric parameters over a first set of wavelengths to determine film layer thicknesses and optical constants of the film layers over the first set of wavelengths. The instrument also measures the sample…
Edge gripped substrate lift mechanism
Granted: February 5, 2002
Patent Number:
6343905
A substrate lift mechanism includes a plurality of fingers mounted on a hoop controlled by an actuator to transfer a substrate, such as a wafer or a flat panel display, from an edge grip arm to a chuck on a processing tool, such as integrated metrology tools. The substrate lift mechanism includes a base that is configured to be mounted to existing processing tools thereby allowing the processing tools to be adapted to be operable with new edge grip arms. The plurality of fingers are…
System using a polar coordinate stage and continuous image rotation to compensate for stage rotation
Granted: November 20, 2001
Patent Number:
6320609
A method for controlling a polar coordinate stage moves an object relative to an imaging system. While moving the object, the image of the object is rotated to compensate for rotation of the object. Accordingly, the orientations of features in the image are preserved, and removal of apparent rotation in the image reduces confusion an operator experiences while directing movement of the object. The angular velocity of the motion of the object is controlled so that image shift speed is…
Compact optical reflectometer system
Granted: January 30, 2001
Patent Number:
6181427
A highly compact reflectometer system (10) for obtaining reflectance data and images from a sample (18). The reflectometer includes a light source (20) for generating a beam (Bi), a beam splitter (44) for transmitting a portion of the beam toward the sample, a lens (52) for focusing the transmitted light onto the sample, a video camera (104) for viewing a field of view (56) created by the light focused on the sample, and a spectrometer (86) for detecting and analyzing the spectrum of the…
Sample support with a non-reflecting sample supporting surface
Granted: August 22, 2000
Patent Number:
6108077
An optical measurement instrument that detects and analyzes reflected light includes a sample support, such as a wafer supporting chuck, with a sample bearing surface that is configured so as to not reflect light back to the optical measurement instrument. In one embodiment, the sample bearing surface of the sample support is a layer of material that absorbs light in the wavelength or wavelengths being used by the optical measurement instrument. For example, a hard plastic, such as…
Integrated optical measurement instruments
Granted: August 24, 1999
Patent Number:
5943122
A measuring instrument with a parfocal combination of an ultra-violet to near-infrared (UV-NIR) spectrophotometer and a Fourier Transform Infrared (FTIR) spectrometer is disclosed. The parfocal configuration of metrology tools obviates lateral movement of the sample between two separate measurement instruments. Consequently, the area occupied by the parfocal measuring instrument is reduced. Moreover, throughput is increased because there is no need to reposition the sample to properly…
Precision weighing to monitor the thickness and uniformity of deposited or etched thin film
Granted: April 29, 1997
Patent Number:
5625170
A time delayed differential weighing procedure used with an electronic analytical balance is optimized for samples exhibiting a small change in mass, for example from deposition, etching, plating or corroding, relative to the sample mass to minimize all significant sources of error that could otherwise degrade the measurement results, such as errors resulting from air density and temperature changes that occur during the interval between the first measurement of a sample, before the…
Scatter correction in reflectivity measurements
Granted: September 19, 1995
Patent Number:
5452091
The correction for scattered light reflected from a substrate having surface irregularities and the measurement of thin film thickness on that substrate are made using a spectrophotometer system and the Fresnel reflectance equation.
Method for determining absolute reflectance of a material in the ultraviolet range
Granted: November 8, 1994
Patent Number:
RE34783
A method for determining a value of absolute reflectance of a material at .[.a predetermined.]. .Iadd.any .Iaddend.wavelength, in the ultraviolet range from its measured reflectance which includes system losses contributed by optics, illumination sources, detectors, etc. The method involves the measurement of reflectance from a known material such as single crystal silicon whose absolute reflectance is well known, dividing the measured value by the absolute value to obtain a system…
Wide band non-coated beam splitter
Granted: November 17, 1992
Patent Number:
5164857
A very wide band beam splitter for operation in the range between deep ultraviolet of 190 nanometers and into infrared is comprised of uncoated transparent material only 0.10 to 0.15 mm. in thickness.
Method for determining absolute reflectance of a material in the ultraviolet range
Granted: September 3, 1991
Patent Number:
5045704
A method for determining a value of absolute reflectance of a material at a predetermined wavelength, in the ultraviolet range from its measured reflectance which includes system losses contributed by optics, illumination sources, detectors, etc. The method involves the measurement of reflectance from a known material such as single crystal silicon whose absolute reflectance is well known, dividing the measured value by the absolute value to obtain a system efficiency coefficient at the…
