Kenneth Dwayne Womack

US Patent:

6677565, Jan 13, 2004

Filed:

Aug 18, 1998

Appl. No.:

09/135734

Inventors:

Michael Hermann Wahl - San Diego CA
Kenneth Howard Womack - San Diego CA
Phillip Gregory Roberts - San Diego CA

Assignee:

Veeco Tucson Inc. - Tucson AZ

International Classification:

G02B 704

US Classification:

2502013, 2505593

Abstract:

The present invention provides a method and apparatus for high-speed autofocus and tilt of an inspection surface in a microscope system. The method and apparatus herein described projects an array of spots, lines, circles, grids or other shapes on the surface to be adjusted. The superposition of the array on the surface is imaged by a CCD camera and captured for subsequent analysis. Analysis of the captured image determines both the distance and angle through which the surface must be adjusted to bring it into the focal plane of the optical system. Focus and tilt error is estimated by comparing image dilation and distortion with calibrated data.

US Patent:

56381786, Jun 10, 1997

Filed:

Sep 1, 1995

Appl. No.:

8/522553

Inventors:

Christopher A. Lacey - San Diego CA
Kenneth H. Womack - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 1114

US Classification:

356369

Abstract:

An apparatus and method for measuring the space between a transparent member such as a disk, and reflective member such as a slider, by detecting a change of polarization of a reflected light beam. The apparatus includes a light source that emits a light beam. The light beam is circularly polarized and directed onto the disk and reflected off of the interface between the disk and the slider. The reflected light beam is split into four separately polarized beams by a beam splitter/polarizer assembly. The four light beams have varying intensities that are measured by photodetectors. Stokes parameters are computed from electrical signals that are generated by the photodetectors. The Stokes parameters correlate to the change in polarization of the reflected light beam. Ellipsometric parameters delta and psi are computed from the Stokes parameters. The thickness of the space and the complex index of refraction (n and K) of the slider are computed from the delta and psi parameters, typically by computing two separate sets of ellipsometric parameters at two different spacing thicknesses.

US Patent:

56965850, Dec 9, 1997

Filed:

Dec 13, 1996

Appl. No.:

8/766900

Inventors:

Michael Wahl - San Diego CA
Kenneth H. Womack - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 902
G11B 3314
G01J 560

US Classification:

356357

Abstract:

An electrostatic discharge device for a flying height tester which measures the air gap of a recording head. The tester includes a transparent disk that is rotated by a spindle motor. The spindle motor is mounted to a spin stand. The tester has a manifold that is mounted to the spin stand and directs a flow of ionized fluid to a bottom surface of the disk. The manifold is also electrically grounded. The ionized fluid and electrically grounded manifold provide an electrical path that discharge electrostatic charge located on the bottom surface of the disk. The manifold extends from an inner disk diameter to an outer disk diameter so that ionized fluid is introduced to the entire bottom surface of the rotating disk. Additionally, the manifold location is such that the ionized fluid provides an electrical path from the disk to the manifold that is relatively constant across the surface of the disk. The manifold location insures that the electrostatic charge is discharged from the entire bottom surface of the disk.

US Patent:

57812993, Jul 14, 1998

Filed:

Sep 24, 1996

Appl. No.:

8/719252

Inventors:

Kenneth H. Womack - San Diego CA
L. Allan Butler - Carlsbad CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 1102
G01N 2141

US Classification:

356357

Abstract:

An apparatus and method for optically measuring the air gap between a transparent glass disk and an air bearing slider without separately measuring the real index of refraction n and extinction coefficient k of the slider using an external ellipsometer. The phase offset required to compute the air gap is computed from a measurement of the air slider reflectivity and from an empirically derived equation that correlates the index of refraction with the reflectance of the slider. The apparatus includes a light source for directing a light beam through the transparent member and air gap, and onto the reflective slider. The light reflects off of the slider and the transparent member to create an interference pattern. The reflected light is detected by a photodetector that is coupled to a computer. The slider reflectivity r is found from the reflected light.

US Patent:

58750290, Feb 23, 1999

Filed:

Aug 11, 1997

Appl. No.:

8/908061

Inventors:

Peter C. Jann - Santa Clara CA
Wayne W. Li - Fremont CA
Igor Iosilevsky - Hayward CA
Kenneth H. Womack - San Diego CA
Vlastimil Cejna - Mountain View CA
George A. Burt - Fremont CA

Assignee:

Phase Metrics, Inc. - San Diego CA

International Classification:

G01B 902

US Classification:

356345

Abstract:

A simple yet versatile noncontact optical inspection instrument and method are described for the inspection of magnetic disk surfaces for surface defects. This instrument is capable of inspecting the disk surface at any point in the disk manufacturing process. Surface defects such as bumps, pits and scratches can be measured. Surface contaminants such as particles and stains can also be measured. The instrument is also capable of discriminating between surface defects and surface contaminants. The instrument is comprised of two identical optical sensors which are located on opposite sides of the disk. A carriage supports and translates these sensors along the disk radius while a spindle rotates the disk. Both surfaces of the disk are therefore simultaneously scanned in a spiral fashion. The sensor's illumination optics produce a monochromatic focused spot of light which is normally incident upon the disk surface.

US Patent:

58087362, Sep 15, 1998

Filed:

Sep 24, 1996

Appl. No.:

8/718899

Inventors:

Kenneth H. Womack - San Diego CA
Carlos A. Duran - San Diego CA
Christopher A. Lacey - San Diego CA

Assignee:

Phase Metrics, Inc. - San Diego CA

International Classification:

G01J 102

US Classification:

356243

Abstract:

A calibration medium that is used to calibrate a flying height tester which measures the gap of an air bearing formed between a magnetic recording head and a substrate. The medium contains a first ridge and a second ridge that extend from an underlying substrate. The ridges may be coated with a reflective material. A flying height tester can be calibrated by measuring light reflected from each ridge. The ridges have varying thicknesses so that the calibration medium will produce multiple data points.

US Patent:

63142120, Nov 6, 2001

Filed:

Mar 2, 1999

Appl. No.:

9/260599

Inventors:

Kenneth Howard Womack - San Diego CA
Daniel Lee Abraham - Irvine CA

Assignee:

Veeco Instruments Inc. - Plainview NY

International Classification:

G06K 936

US Classification:

382286

Abstract:

The present invention provides a method and apparatus for high precision image metrology. A feature dimension from the image is determined by measuring corresponding features in the Fourier power spectrum of the image with substantially improved precision due to immunity from noise and system response. Operationally, a digital image of the sample is acquired at sufficient resolution to capture the feature of interest. A sample widow is chosen which substantially isolates the feature of interest. The feature window is then piecewise extended to a predetermined window size for effective Fourier Transform interpolation. A Fourier Power Spectrum of the sample widow is generated at high sample density such that the loci of extremal points indicative of a feature dimension is identified with high precision. The relative spacing of the extremal points is measured and related to the desired feature dimension. Utilizing the power spectrum of the image feature in the manner herein disclosed advantageously provides a way to measure feature dimensions with high precision.

US Patent:

57777403, Jul 7, 1998

Filed:

Feb 27, 1997

Appl. No.:

8/807669

Inventors:

Christopher A. Lacey - San Diego CA
Kenneth H. Womack - San Diego CA

Assignee:

Phase Metrics - San Diego CA

International Classification:

G01B 902

US Classification:

356357

Abstract:

An apparatus and method for measuring the topographic profile of a reflective member having an index of refraction. The apparatus comprises a first optical system that reflects a light beam from the reflective member and detects the reflected light beam. A second optical system directs the light beam to interfere with the reflected light beam and detects the resulting interference pattern. A processor coupled to the first optical system and the second optical system computes the index of refraction of the reflective member from the detected reflected light beam and provides the topographic profile of the reflective member from the index of refraction and the interference pattern.