Water lift mechanism with electrostatic pickup and method for transferring a workpiece

An apparatus for transferring a semiconductor wafer from an end effector located within a vacuum chamber to a pre/post processing chamber located above the vacuum chamber comprising:

• a bipolar electrostatic pickup for engaging the semiconductor wafer at an off-center position near an edge thereof;
• a transfer arm, said electrostatic pickup positioned near a first end of said transfer arm on an upper surface thereof;
• and
• a linear lift and rotary drive mechanism connected to a second end of the transfer arm for rotating the transfer arm and electrostatic pickup in a theta axis and vertically moving the transfer arm and electrostatic pickup in a z-axis.

An apparatus for processing semiconductor wafers comprising:

• a central transfer chamber having a wafer transfer robot therein for transferring wafers on a first processing plane;
• a plurality of process chambers surrounding and connected to said central transfer chamber on said processing plane;
• a pre/post processing transfer chamber located above said central transfer chamber, the pre-post processing transfer chamber for transferring wafers on a pre/post processing plane;
• a wafer transfer device for engaging the semiconductor wafer at an off-center position and transferring the wafer between the robot in the first processing plane and the pre/post processing transfer chamber, wherein said central and pre/post transfer chambers may be sealed from one another;
• said wafer transfer device comprises:
• a bipolar electrostatic pickup for engaging the semiconductor wafer at an off-center position near an edge thereof;
• a transfer arm, said electrostatic pickup positioned near a first end of said transfer arm on an upper surface thereof;
• and
• drive means for rotating the transfer arm and electrostatic pickup in the theta axis, or vertically moving the transfer arm and electrostatic pickup in the z-axis.

A method for transferring an article both in a z-axis and a theta axis comprising:

• engaging the article with an electrostatic pickup at an off-center position near an edge thereof;
• rotating a transfer arm carrying said electrostatic pickup in the theta axis;
• and
• vertically moving the article carried by the transfer arm and electrostatic pickup in the z-axis.

A method for transferring a semiconductor wafer from an end effector located within a vacuum chamber to a pre/post processing transfer chamber located above the vacuum chamber comprising:

• positioning an electrostatic pickup carried on a transfer arm below the semiconductor wafer;
• rotating the arm to position the electrostatic pickup at a point below and off-center of the semiconductor wafer;
• raising the electrostatic pickup to contact a lower surface of the semiconductor wafer at an off-center position near the edge thereof;
• and
• energizing the electrostatic pickup to create and attraction force on the article;
• rotating the transfer arm carrying said electrostatic pickup in the theta axis;
• and
• raising the semiconductor from a processing plane located within the vacuum chamber to a pre/post processing plane located within the pre/post processing transfer chamber, wherein the pre/post processing transfer chamber is located above and sealably separable from the vacuum chamber.

An apparatus for transferring a substrate in both longitudinal and arcuate motions comprising:

• an electrostatic pickup for engaging the substrate at an off-center position near an edge thereof;
• a transfer arm, said electrostatic pickup positioned near a first end of said transfer arm on an upper surface thereof;
• and
• drive means for rotating one end of said transfer arm and thereby sweep said electrostatic pickup in an arc, and for vertically moving the transfer arm and electrostatic pickup in a longitudinal direction, wherein the electrostatic pick-up is connected to a power source by inductive coupling.