Wyko, Inc.

Veeco Corporation

John B Hayes

Eric M Frey

Jamshid Jahanmir

Bryan W Guenther

Chiayu Ai

Paul J Caber

An optical crossed grating is used to calibrate a conventional autocollimator operated with a single-frequency light source. Since a collimated monochromatic beam is diffracted at a number of well known angles after being reflected from the grating, an array of spots is formed on the detector surface that makes it possible to calibrate the autocollimator in a single operation. Because the angle of the diffracted light is determined only by the spacing in the grid, the calibration accuracy is insensitive to temperature variations and to the position of the grid on the sample stage. The calibration scaling values are calculated simply by measuring the spot spacings on the detector surface in relation to the diffraction angles corresponding to the grid spacing.

Autocollimator with grating

An autocollimator/point-range sensor system produces a linearly polarized light beam that is split into a point-range sensor beam and an autocollimator beam. The linearly polarized point-range sensor beam is utilized to carry out z-position measurements according to prior-art techniques. The autocollimator beam is passed through a quarter-wave plate to introduce a 90-degree phase shift and convert it to circularly polarized light. An analyzer placed in front of the autocollimator detector is positioned such that its transmission axis is offset with respect to the plane of polarization of the linearly polarized point-range sensor beam, thereby blocking any scattered light from the sensor beam while passing a component of the circularly-polarized autocollimator light to reach the detector.

System for eliminating scattered light in autocollimator for

An interchangeable clamp plate is designed to receive and hold a magnetic-head suspension in a predetermined position in a test clamp of a pitch and roll measuring instrument. The clamp plate comprises a support plate for securing the swage mount of the suspension to a predetermined reference plane and a reference surface integrally formed coplanarly with the support plate in a position within the normal operating range of the optics of the instrument. Each kind of suspension being tested is mounted on a clamp plate conforming to its specific geometry that is adapted for installation in the test instrument prior to measurement. As a result of this configuration, once the instrument is calibrated with respect to the reference surface coplanar with the swage mounting surface, measurement accuracy is inherently maintained during testing. Upon switching to a different kind of suspension, a new clamp plate with a similar integral and coplanar reference surface is installed in the instrument's clamp and used to recalibrate it before test measurements are performed on the new suspension.

Interchangeable sample stage with integral reference surface for

A scanning interferometer that utilizes a DC gear motor instead of a PZT translator in closed-loop configuration with an LVTD position sensor. The DC motor is connected to the scanning mechanism so that a rotational motion of the motor shaft produces a translation along the optical axis of either the sample or the objective of the interferometer. During scanning, the motor is driven by the input of a ramp signal into the system. The closed-loop configuration is such that a constant, or nearly constant voltage is applied to the DC motor to produce a constant-speed scan in response to the ramp input. Any non-linearity in the speed of motion is corrected by an adjustment to the motor voltage. At the completion of the scan, the ramp input is removed and the motor is automatically returned to the starting position to satisfy the closed-loop condition. In order to maintain the image in focus on the sensor over the wide range of scanning, a pair of relay lenses is inserted in the optical path between the interferometer and the light detector.

Combination of motorized and piezoelectric translation for long-range

A scanning probe microscope includes a base, an inner piezoelectric tube, and an outer PMN translator arrangement including three PMN posts, with first ends of the PMN posts connected to the base. A first end of the inner piezoelectric tube is rigidly connected to second ends of the PMN posts. Inner quadrant conductors are disposed on the inner surfaces of the inner piezoelectric tube, and outer quadrant conductors are disposed on the outer surfaces of the inner piezoelectric tube. Separate x and y scan control voltage signals are applied to corresponding opposed quadrant conductors of the inner piezoelectric tube to control scanning of the free end of the inner tube in the x and y directions. A z scan control voltage is produced by a servo control circuit in response to a probe signal and applied to the PMN posts, which have negligible hysteresis. The servo control circuit refers to a look-up table to correct non-linearities of the PMN posts.

PMN translator and linearization system in scanning probe microscope

A scanning probe microscope includes a base, an inner piezoelectric tube, and an outer piezoelectric tube, with a first end of the outer piezoelectric tube connected to the base. A first end of the inner piezoelectric tube is rigidly connected to a second end of the outer piezoelectric tube. Thin inner conductors are disposed on the inner surfaces of the inner piezoelectric tube and the outer piezoelectric tube, and quadrant conductors are disposed on the outer surfaces of the inner piezoelectric tube and the outer piezoelectric tube. Separate x, y, and z scan control voltage signals are applied to various quadrant conductors of the inner and outer piezoelectric tubes to control scanning of the free end of the inner tube in the x, y, and z directions, respectively.

Compact temperature-compensated tube-type scanning probe with large scan

A scanning probe microscope includes a base, an inner piezoelectric tube, and an outer piezoelectric tube, with a first end of the outer piezoelectric tube connected to the base. A first end of the inner piezoelectric tube is rigidly connected to a second end of the outer piezoelectric tube. Thin inner conductors are disposed on the inner surfaces of the inner piezoelectric tube and the other piezoelectric tube, and quadrant conductors are disposed on the outer surfaces of the inner piezoelectric tube and the outer piezoelectric tube. Variable voltages are applied to the quadrant conductors of the outer piezoelectric tube and the inner piezoelectric tube and varied to cause lateral and axial movement of the second end of the outer piezoelectric tube and also to cause lateral and perpendicular movement of the second end of the inner piezoelectric tube relative to its first end. A probe having a tip is connected to the second end of the inner piezoelectric tube and scans the surface of a sample in response to the applied quadrant conductor voltages. A control system senses current or other parameter sensed by the tip of the probe and indicative of distance of the probe tip from the scanned surface to control application of the quadrant voltages.

A method and apparatus is disclosed for aligning a reflective surface with an alignment axis in a representative environment of an interferometer. An image of the reflective surface is focused onto a diffuse screen to form a spot image thereon. Rays of the spot image emanating from the diffuse screen are collimated. Some of the collimated rays are focused onto a detector to form a non-inverted image spot. A portion of the collimated rays are intercepted and inverted by means of an image inverter aligned with the alignment axis. The inverted rays are focused onto the detector to form an inverted image spot. The reflecting surface is moved so as to cause the inverted image spot and the non-inverted image spot to coincide, at which point the reflecting surface is aligned with the alignment axis.

Optical alignment system utilizing alignment spot produced by image

An interferometer includes a thin, absorbing pellicle in the path of a test beam to attenuate the test beam so that its intensity is approximately equal to the intensity of a reference beam. The pellicle reflects less than about six percent of the test beam, thereby avoiding spurious reflections that produce spurious fringes.

Interferometer with thin absorbing beam equalizing pellicle

The translation device includes first and second plates, one movable relative to the other in response to a plurality of piezoelectric transducers. A flexure is located between the first and second plates and attached to each of them to spring-load the piezoelectric transducers. The driver circuit produces voltages which are balanced and applied to the piezoelectric transducers to produce tilt-free translation of the first plate relative to the second.

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Tucson, AZ, United States of America

John B Hayes