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AssigneeApplied Materials, Inc.
InventorsRobert Mitchell, James Biddle, Ian R. Joyce, James Victor Edwards
Estimating the term…
The correct handover position between the gripper and the e-chuck is located using a light source and a 2-D photosensor. As the e-chuck is in the loading position it can be driven forwards or backwards in the beam direction by rotating the main whisper scan rotor. The line drawn across the 2-D array by a spot of light from the light source passing through a hole in a flag attached to the e-chuck is recorded. Similarly, the line drawn by a spot of light from the same source passing through a hole in the flag attached to the gripper is also recorded. The point of intersection is the ideal transfer point. For transfer the e-chuck is then driven to this point which can be checked from the 2-D sensor. The gripper is then also driven to the same point and alignment can be checked using the light source and sensor. The hole in the gripper flag may be somewhat smaller than the hole in the e-chuck flag so that proper alignment is assured when the illuminated spot on the 2-D sensor is at the target position for the e-check but has the dimension or total brightness corresponding to the smaller hole of the gripper.
An ion implantation apparatus having a gripper arm which, in use, transfers a wafer within a vacuum chamber between a loading position and a processing position, and an e-chuck on which, in use, the wafer is retained while it is scanned by an ion beam, and including apparatus for detecting that said gripper arm and said e-chuck are correctly positioned relatively to one another in a predetermined position, said detecting apparatus comprising a light source, a light sensor onto which light from the light source is projected, in use, and a respective flag on each of said gripper arm and said e-chuck, each said flag producing, in use, a characteristic shadow on the light detector when the gripper arm and the e-chuck are in the predetermined position, the characteristic shadows of the flags being different from one another.
A method of calibrating an apparatus having a pair of moveable arms which are driveable to a handoff position to pass a component from one arm to the other, a position sensitive light sensor, and a light source emitting light towards the light sensor, wherein each arm has a flag which produces its own characteristic signal at the light sensor when interposed between the light source and the light sensor, the method comprising the steps of scanning the first arm across the sensor, recording the readings produced by the first flag across the sensor, scanning the second arm across the sensor, recording the readings produced by the second flag across the sensor, and calculating from the two sets of readings the position where the two flags coincide which represents the handoff position.
A method of operating ion implantation apparatus having a gripper arm for transferring a wafer within a vacuum chamber between a loading position and a processing position and an e-chuck to retain the wafer while it is scanned by an ion beam, the method being for detecting that the gripper arm and the e-chuck are correctly positioned relatively to one another at a predetermined position, and comprising emitting a beam of light from a light source towards a light sensor, moving the gripper arm and the e-chuck so that a flag on each of them produces a characteristic shadow on the light detector when in the predetermined position, and detecting that the gripper arm and the e-chuck are in the correct alignment when both characteristic shadows are simultaneously recognized on the light sensor.
Dependencies are inferred from the claim text.