Wafer position correction with a dual, side-by-side wafer transfer robot
AssigneeNovellus Systems, Inc.
InventorsDamon Genetti, Shawn Hamilton, Rich Blank, Sheldon Templeton
Life of this patent
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Abstract
Methods and systems for positioning wafers using a dual side-by-side end effector robot are provided. The methods involve performing place moves using dual side-by-side end effector robots with active wafer position correction. According to various embodiments, the methods may be used for placement into a process module, loadlock or other destination by a dual wafer transfer robot. The methods provide nearly double the throughput of a single wafer transfer schemes by transferring two wafers with the same number of moves.
Claims14
A method comprising:
- picking first and second wafers with a dual side-by-side end effector robot such that each end effector holds a wafer;
- moving the dual end effector robot according to a nominal path to a nominal hand-off position;
- measuring the position of the first and second wafers, wherein wafer position is measured during a retraction move;
- calculating placement corrections for first and second wafers;
- extending and rotating the dual end effector robot to correct the placement of the first wafer;
- placing the first wafer at a first wafer hand-off position;
- after placing the first wafer at a first wafer hand-off position, extending and rotating the dual end effector robot to correct the placement the second wafer;
- and
- placing the second wafer at a second wafer hand-off position.
A wafer transfer system for transferring two wafers from a first location to a second location, comprising:
- a) a transfer module comprising a dual side-by-side end effector robot, wherein said dual end effectors positions in space are fixed relative to each other;
- b) first and second side-by-side stations located at the second location, each station comprising lift pins;
- c) a first controller, wherein said controller controls picking the wafers from the first location with the dual end effector robot such that each end effector holds a wafer, moving the dual end effector robot according to a nominal path to a nominal hand-off position at the second location, measuring the position of the first and second wafers, calculating placement corrections for first and second wafers, extending and rotating the dual end effector robot to correct the placement of the first wafer, lifting the lift pins at the first station to place one wafer at the first station;
- extending and rotating the dual end effector robot to correct the placement the second wafer;
- and lifting the lift pins at the second station to place one wafer at the second station;
- and
- d) a process module controller separate from the first controller, wherein the lift pins are independently controllable by both the process module controller and the first controller.
A method comprising:
- picking first and second wafers with a dual side-by-side end effector robot such that each end effector holds a wafer;
- moving the dual end effector robot according to a nominal path to a nominal hand-off position;
- measuring the position of the first and second wafers;
- calculating placement corrections for first and second wafers;
- extending and rotating the dual end effector robot to correct the placement of the first wafer;
- placing the first wafer on a first fixed support at a first wafer hand-off position;
- after placing the first wafer at a first wafer hand-off position, extending and rotating the dual end effector robot to correct the placement the second wafer;
- and
- placing the second wafer on second fixed support at a second wafer hand-off position, wherein the first and second fixed supports are at different heights.
Dependencies are inferred from the claim text.