Alignment Correction System and Method of Use
AssigneeInternational Business Machines Corporation
InventorsRobert J. Foster, Lin Zhou, Shahin Zangooie, Roger M. Young, Clemente Bottini
Life of this patent
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Abstract
A system and method for correcting alignment of a product on a tool and, more particularly, to a system and method for correcting alignment of a wafer on a chuck of a tool. The system is a tool comprising at least one contact near a circumference of the tool and a grounded contact proximate to the at least one contact. The method comprises measuring current on each branch of a circuit and calculating an angle of a wafer based on a difference in the current on each branch of the circuit.
Claims4
1-30. (canceled)
A tool, comprising:
- at least one contact near a circumference of the tool;
- a grounded contact proximate to the at least one contact;
- at least one spring on an underside of the contact to provide an upward biasing force;
- an independently moveable inner cylinder or plate on the tool;
- and
- a computing infrastructure having executable code configured to calculate an angle of displacement of a wafer based on measured resistances of opposing branches of the at least one contact from a point of electrical contact with the wafer, wherein
- the at least one contact:
- is coupled to ammeters via low resistance connecting wires comprised of one of silver, copper, aluminum, gold and platinum,
- is at least one arc shaped contact and is made of one of Manganin, copper, platinum and aluminum, and
- is at least two contacts and the computing infrastructure calculates a centering alignment of the wafer on the tool based on a triangulation of contacts on a backside of the wafer and two of the at least two contacts,
- the at least one contact and grounded contact form a closed circuit when a contact on a back of a wafer bridges a gap therebetween,
- the independently moveable inner cylinder or plate is configured to lift, rotate and lower a wafer to adjust an alignment angle of the wafer, and
- the independently moveable inner cylinder or plate is controllable by a control.
A computer program product comprising a computer usable medium having readable program code embodied in the medium, the computer program product includes at least one component to perform the processes of calculating an angle of displacement of a wafer based on measured resistance of opposing branches of a contact from a point of electrical contact with the wafer, wherein the at least one component performs the processes of calculating a centering of the wafer on the tool based on a triangulation of contacts on a backside of the wafer and at least two contacts on a chuck holding the wafer.
A method, comprising:
- measuring current on each branch of a circuit;
- calculating an angle of a wafer based on a difference in the current on each branch of the circuit;
- calculating a centering alignment of the wafer on a chuck using triangulation data obtained from contacts on a backside of the wafer and contacts on the chuck;
- and
- lifting, rotating and lowering the wafer using an inner cylinder or plate in order to correct alignment of the wafer based on the calculating, wherein
- the calculating the angle of the wafer comprises:
- θ
- =
- A
-
- (
- V
- 1
- I
- 1
- -
- V
- 2
- I
- 2
- )
- 2
-
- ρ
-
-
- r
- c
-
- [
- radians
- ]
- coarse and fine wafer alignment is provided using a single dual conductive arc layout.
Dependencies are inferred from the claim text.