Laser detection of wafer type and orientation
OwnerFHM Faridur Rahmaninventor
Life of this patent
Estimating the term…
Abstract
A system includes a stage that is configured to hold a workpiece in a chamber. A light source is configured to direct an incident beam at a surface of the workpiece on the stage. The incident beam is directed at the surface of the workpiece at an incident angle, θ, with respect to a normal axis to the surface. A detector is configured to measure intensity of the incident beam reflected off the workpiece. A processor is configured to determine an orientation of the workpiece relative to the stage using measurements of the intensity.
Claims20
A system comprising:
- a chamber;
- a stage configured to hold a workpiece, wherein the stage is disposed within the chamber;
- a light source configured to direct an incident beam at a surface of the workpiece on the stage, wherein the incident beam is directed at the surface of the workpiece at an incident angle, θ, with respect to a normal axis to the surface;
- a detector configured to measure intensity of the incident beam reflected off the workpiece;
- and
- a processor in electronic communication with the detector, wherein the processor is configured to determine an orientation of the workpiece relative to the stage using measurements of the intensity.
A method comprising:
- directing an incident beam from a light source at a workpiece on a stage in a chamber, wherein the incident beam is directed at a surface of the workpiece at an incident angle, θ, with respect to a normal axis to the surface;
- reflecting the incident beam off the surface of the workpiece;
- measuring intensity of the incident beam that is reflected off the workpiece;
- and
- determining, using a processor, an orientation of the workpiece relative to the stage using measurements of the intensity.
A non-transitory computer-readable storage medium, comprising one or more programs for executing the following steps on one or more computing devices:
- receiving measurements of intensity of an incident beam of light reflected off a surface of a workpiece on a stage, wherein the incident beam is directed at a surface of the workpiece at an incident angle, θ, with respect to a normal axis to the surface;
- and
- determining an orientation of the workpiece relative to the stage using measurements of the intensity.
Dependencies are inferred from the claim text.