Richard A Yarussi

US Patent:

6522406, Feb 18, 2003

Filed:

Jun 7, 2001

Appl. No.:

09/877363

Inventors:

Pablo I. Rovira - San Francisco CA
Richard A. Yarussi - San Francisco CA
James M. Holden - San Jose CA
Roger R. Lowe-Webb - Mountain View CA

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01J 400

US Classification:

356369, 356364, 250225

Abstract:

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 measured irradiance and the modeled angular dependence, the total irradiance of the metrology tool can be determined, which is independent of the angle of the rotatable polarizer. The irradiance, e. g. , reference and/or back reflection, can then be determined for any desired angle of the rotatable polarizer using the total irradiance and the angular dependence of the metrology tool.

US Patent:

6665070, Dec 16, 2003

Filed:

Jun 7, 2001

Appl. No.:

09/878069

Inventors:

Richard A. Yarussi - San Francisco CA
Pablo I. Rovira - San Francisco CA

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01J 3447

US Classification:

356369, 356364, 356327, 356328, 250225

Abstract:

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, the sample offset angle between the axis of motion of the stage and the axis of orientation of a sample is measured. The polarizer offset angle, which is the angle between transmission axis of the polarizer and the axis of orientation of the sample, is the sum of the system offset angle and the sample offset angle. Thus, by rotating the polarizer by an amount equivalent to the sum of the system offset angle and the sample offset angle, the polarizer offset angle is reduced to zero. If desired, the polarizer may be rotated once to compensate for the system offset angle and then rotated to compensate for the sample offset angle for each newly loaded substrate or the polarizer may be rotated to compensate for both the system offset angle and the sample offset angle for each newly loaded substrate.

US Patent:

7115858, Oct 3, 2006

Filed:

Sep 25, 2000

Appl. No.:

09/670000

Inventors:

James M. Holden - San Jose CA, US
William A. McGahan - Spicewood TX, US
Richard A. Yarussi - San Francisco CA, US
Pablo I. Rovira - San Francisco CA, US
Roger R. Lowe-Webb - Mountain View CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G02F 1/01
G01J 4/00

US Classification:

250225, 356369

Abstract:

A normal incidence reflectometer includes a rotatable analyzer/polarizer, which permits measurement of a diffracting structure. Relative rotation of the analyzer/polarizer with respect to the diffracting structure permits analysis of the diffracted radiation at multiple polarity orientations. A spectograph detects the intensity of the spectral components at different polarity orientations. Because the normal incidence reflectometer uses normally incident radiation and an analyzer/polarizer that rotates relative to the diffracting structure, or vice-versa, the orientation of the diffracting structure does not affect the accuracy of the measurement. Thus, the sample holding stage may use X, Y, and Z, as well as r-θ type movement and there is no requirement that the polarization orientation of the incident light be aligned with the grating of the diffraction structure. A non-linear multivariate regression process is used to adjust the parameters of an optical model, such as rigorous coupled-wave analysis, to provide a match with the measured data.

US Patent:

7289215, Oct 30, 2007

Filed:

Jan 18, 2007

Appl. No.:

11/624666

Inventors:

Blaine R. Spady - Lincoln NE, US
John D. Heaton - Fremont CA, US
Robert Buchanan - Pleasanton CA, US
Richard A. Yarussi - San Francisco CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01B 11/00
G01B 11/14
G01N 21/00
G06K 9/00

US Classification:

356401, 3562371, 356614, 382141, 382145, 382151

Abstract:

A metrology system includes a positioning system that produces linear and rotational motion between an imaging system and the wafer. The imaging system produces signals representing the image of the wafer in the field of view of the imaging system. A control system receives and processes the image signals, and generates corrected signals that compensate for rotational movement between the imaging system and the wafer. In response to the corrected signals, a monitor displays an image with the orientation of features on the wafer within the field of view unaffected by the rotational movement.

US Patent:

7295314, Nov 13, 2007

Filed:

Dec 8, 1999

Appl. No.:

09/458123

Inventors:

Blaine R. Spady - Lincoln NE, US
John D. Heaton - Fremont CA, US
Robert Buchanan - Pleasanton CA, US
Richard A. Yarussi - San Francisco CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01B 11/00
G01B 11/14
G01N 21/00
G06K 9/00

US Classification:

356401, 3562371, 356614, 382141, 382145, 382151

Abstract:

A metrology/inspection system moves the imaging and/or measuring equipment of the system relative to a wafer. Accordingly, measurement or inspection of the wafer does not require that the wafer be mounted on a precision stage. This allows the wafer to be at rest on any structure native in a processing apparatus when the system measures or inspects the wafer. Accordingly, measurement does not require removing the wafer from the processing apparatus and does not delay processing since the wafer can be measured, for example, during a required cool down period of device fabrication process. Alignment of an optical system includes pre-alignment base on edge detection using the optical system and more precise alignment using image recognition. An R-θ stage can position the optical system at inspection areas on the wafer. Image rotation can provide a fixed orientation for all images at the various inspection areas and can maintain the fixed orientation when moving from one inspection area to the next.

US Patent:

7372565, May 13, 2008

Filed:

Sep 28, 2006

Appl. No.:

11/540990

Inventors:

James M. Holden - San Jose CA, US
William A. McGahan - Spicewood TX, US
Richard A. Yarussi - San Francisco CA, US
Pablo I. Rovira - San Francisco CA, US
Roger R. Lowe-Webb - Mountain View CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01J 3/28

US Classification:

356327

Abstract:

A normal incidence reflectometer includes a rotatable analyzer/polarizer for measurement of a diffracting structure. Relative rotation of the analyzer/polarizer with respect to the diffracting structure permits analysis of the diffracted radiation at multiple polarity orientations. A spectograph detects the intensity of the spectral components at different polarity orientations. Because the normal incidence reflectometer uses normally incident radiation and an analyzer/polarizer that rotates relative to the diffracting structure, or vice-versa, the orientation of the diffracting structure does not affect the accuracy of the measurement. Thus, the sample holding stage may use X, Y, and Z, as well as r-θ type movement and there is no requirement that the polarization orientation of the incident light be aligned with the grating of the diffraction structure. A non-linear multivariate regression process is used to adjust the parameters of an optical model, such as rigorous coupled-wave analysis, to provide a match with the measured data.

US Patent:

7697135, Apr 13, 2010

Filed:

Jan 17, 2007

Appl. No.:

11/624182

Inventors:

Richard A. Yarussi - San Francisco CA, US
Martin Ebert - Fremont CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01J 3/28

US Classification:

356326

Abstract:

An optical metrology system collects spectral data while scanning over the focal range. The spectral data is evaluated to determine a plurality of peak intensity values for wavelengths in the spectra. The peak intensities are then combined to form the measured spectrum for the sample, which can then be used to determine the sample properties of interest. In one embodiment, the peak intensity is determined based on the measured maximum intensity and a number n of intensity values around the measured maximum intensity, e. g. , using curve fitting. If desired, the number n may be varied as a function of wavelength to vary the effective spot size of the metrology system while optimizing noise performance. The peak intensity may also be derived as the measured maximum intensity or through a statistical analysis.

US Patent:

8259296, Sep 4, 2012

Filed:

Mar 30, 2010

Appl. No.:

12/750577

Inventors:

Richard A. Yarussi - San Francisco CA, US
Martin Ebert - Fremont CA, US

Assignee:

Nanometrics Incorporated - Milpitas CA

International Classification:

G01J 3/28

US Classification:

356326

Abstract:

An optical metrology system collects spectral data while scanning over the focal range. The spectral data is evaluated to determine a plurality of peak intensity values for wavelengths in the spectra. The peak intensities are then combined to form the measured spectrum for the sample, which can then be used to determine the sample properties of interest. In one embodiment, the peak intensity is determined based on the measured maximum intensity and a number n of intensity values around the measured maximum intensity, e. g. , using curve fitting. If desired, the number n may be varied as a function of wavelength to vary the effective spot size of the metrology system while optimizing noise performance. The peak intensity may also be derived as the measured maximum intensity or through a statistical analysis.