Ade Optical Systems Corporation

Other

Sentrol, Inc.

Michael E Fossey

John C Stover

Lee Dante Clementi

Douglas Henry Marman

Kenneth A Zimmerman

Noel S Poduje

Kirk Rodney Johnson

Songping Gao

Mark A Peltier

Douglas W Ford

David S Terrett

Michael Stanbro

John P Desmond

A surface inspection system and method is provided which detects defects such as particles or pits on the surface of a workpiece, such as a silicon wafer, and also distinguishes between pit defects and particle defects. The surface inspection system comprises an inspection station for receiving a workpiece and a scanner positioned and arranged to scan a surface of the workpiece at the inspection station. The scanner includes a light source arranged to project a beam of P-polarized light and a scanner positioned to scan the P-polarized light beam across the surface of the workpiece. The system further provides for detecting differences in the angular distribution of the light scattered from the workpiece and for distinguishing particle defects from pit defects based upon these differences.

Wafer inspection system for distinguishing pits and particles

The composition of a particle occurring on the surface of a smooth substrate is identified by impinging the surface with a light beam having a strong P-polarized component at an oblique angle of incidence to the surface, and collecting light scattered from the surface at forward, center, and back locations relative to the portion of the surface impinged by the incident beam. The intensities of the light collected at these locations are measured by detectors and converted into signals, and the magnitudes of the signals are compared to correlations of particle material as a function of the relative magnitudes of the forward-, center-, and back-scatter signals so as to identify the material whose correlation most nearly matches the measured detector signals. Preferably, a ratio of the back detector signal magnitude to forward detector signal magnitude is correlated with particle material and back detector signal magnitude. Alternatively or additionally, a ratio of back detector signal magnitude to center detector signal magnitude is correlated with particle material and back detector signal magnitude. Average particle diameter versus back detector signal magnitude is correlated with particle material.

Methods and apparatus for identifying the material of a particle

In one aspect, the present invention provides an apparatus for transferring wafers to or from a wafer cassette having a plurality of wafer-receiving slots, wherein the apparatus comprises a wafer paddle which is adapted to be inserted into a wafer cassette alongside a wafer. Edge grippers carried by the wafer paddle releasible grip the wafer by its edges. A first capacitive sensor carried by the wafer paddle is oriented in a first direction for sensing information about a wafer in a wafer receiving slot of the wafer cassette. A second capacitive sensor carried by the wafer paddle is oriented in a direction perpendicular to the first direction for sensing additional proximity information about a wafer in a wafer receiving slot of the cassette. A transport mechanism produces movement of the wafer paddle along at least three axes of movement to permit transferring wafers to or from respective wafer receiving slots of the wafer cassette. In a more specific aspect, the transport mechanism produces movement along five axes: relative translational movement along orthogonal x, y and z axes, rotational movement about a rotational axis, and tilting movement of the wafer paddle about a paddle tilt axis.

Wafer transfer robot

A surface inspection system and methods of inspecting a surface of a workpiece are provided for detecting particles, defects, or other surface characteristics in or on a surface of the workpiece. The surface inspection system preferably has a transporter arranged for transporting a workpiece along a material path and a rotator associated with the transporter and arranged for rotating a workpiece during translational travel along the material path. A scanner is positioned and arranged for scanning a surface of a workpiece during rotational and translational travel along the material path. The scanner preferably includes a light source arranged to generate a light beam therefrom and a deflector positioned to receive the light beam and arranged for deflecting the light beam along a predetermined scan path across a surface of the workpiece as the workpiece rotationally and translationally travels along the material path. A collector also is preferably arranged for collecting light specularly reflected and scattered from the surface of the workpiece during rotational and translational travel along the material path.

Surface inspection system and method of inspecting surface of workpiece

An improved environmental alarm system has centralized control of local sensor display capabilities displays, on the sensor itself, a variety of sensor data including sensor address, and detected levels of one or more environmental conditions. Alphanumeric characters are displayed at individual sensors in response to commands from a master microprocessor directing local sensor display content and timing. A local microcontroller within each sensor interprets the detected signal and prepares a resulting data signal that is available for downloading into the alphanumeric display in compliance with a coded message from the master microprocessor.

Smoke detector with digital display

A digital-based control data processing system detects during system operation the occurrence of data processing errors. Data processing accuracy is verified by receiving output information developed from system input information in accordance with a first operational function, computing a derived version of the system input information in accordance with a second operational function, and comparing the derived version of the system input information to the actual system input information to determine whether they differ by a predetermined operational tolerance. This method for verifying processing accuracy is especially advantageous for detecting latent software errors which are unique to a particular computer program. The processing system includes display apparatus which develops from the output information a set of display symbols that convey the information on a monitor screen to the pilot. Assigned to each display symbol is an identifying tag which identifies in real time a display symbol that conveys erroneous information.

Growing community of inventors

Newbury Park, CA, United States of America

Michael E Fossey