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US 12,745,594 B2Granted
Reticle exchange device with reticle levitation
AssigneeMassachusetts Institute of Technology
InventorsDavid L. Trumper, Brij Mohan Bhushan
Life of this patent
Estimating the term…
Abstract
An electrostatic chuck includes electrodes to clamp a workpiece, electrodes to electrostatically levitate and position the workpiece, and sensors to detect position and orientation of the workpiece. Lateral motion of the workpiece relative to the electrostatic chuck can be damped prior to clamping.
Claims25
A system for exchanging a reticle in a semiconductor processing system, the system for exchanging the reticle comprising:
- a reticle exchange device having a seat for a reticle;
- and
- an electrostatic chuck having at least one clamping surface and one or more clamping electrodes for electrostatically clamping the reticle against the clamping surface;
- a plurality of levitation electrodes to electrostatically levitate the reticle prior to contact with the clamping surface of the electrostatic chuck;
- and
- a control circuit configured to modulate voltage of different ones of the levitation electrodes to control position and orientation of the reticle in six degrees of freedom while maintaining substantially net zero charge on the reticle, wherein the control circuit is further configured to induce a convex geometric deformation in the reticle during levitation such that a center area of the reticle makes contact with the clamping surface prior to edge areas of the reticle.
3 more elements
An electrostatic chuck comprising:
- a surface configured to receive a workpiece;
- one or more clamping electrodes configured to electrostatically attract and clamp the workpiece across an air gap against the surface;
- a plurality of levitation electrodes to electrostatically levitate the workpiece prior to clamping;
- one or more position sensors to detect a position of the workpiece during levitation;
- and
- a circuit coupled to at least one of the one or more clamping electrodes and/or levitation electrodes, the circuit configured to control levitation and clamping of the workpiece, the levitation control including modulating voltage of different ones of the levitation electrodes to control position and orientation of the workpiece in six degrees of freedom while maintaining substantially net zero charge on the workpiece, the circuit further configured transition the workpiece from a first state wherein a center area of the workpiece is even with or lower than edge areas of the workpiece to a second state wherein the center area of the workpiece is actively bowed up above the edge areas of the workpiece prior to the clamping.
3 more elements
A system for exchanging a reticle in a production system, the system for exchanging the reticle comprising:
- a reticle exchange device having a seat for a photolithographic reticle;
- an electrostatic chuck having a surface and one or more electrodes for electrostatically clamping the photolithographic reticle;
- and
- a levitation system comprising a control circuit configured to levitate the photolithographic reticle toward the surface of the electrostatic chuck while controlling position and orientation of the photolithographic reticle in six degrees of freedom and maintaining substantially net zero charge on the reticle, wherein the control circuit is further configured to deform a shape of the photolithographic reticle during the levitation such that a center area of the reticle makes contact with the electrostatic check prior to edge areas of the photolithographic reticle making contact with the electrostatic chuck.
1 more element
A system for exchanging a photolithographic reticle in a photolithographic production system, the system for exchanging the photolithographic reticle comprising:
- a reticle exchange device having a seat for a photolithographic reticle;
- an electrostatic chuck having a surface and one or more clamping electrodes for electrostatically clamping the photolithographic reticle;
- and
- a levitation system for levitating the photolithographic reticle toward the surface of the electrostatic chuck, the levitation system including:
- a plurality of levitation electrodes to levitate the photolithographic reticle prior to clamping by the electrostatic chuck;
- and
- a circuit configured to modulate voltage of different ones of the levitation electrodes to control position and orientation of the photolithographic reticle in six degrees of freedom while maintaining substantially net zero charge wherein the plurality of levitation electrodes comprises an inner center electrode for vertical positioning and an outer center electrode driven to provide a restoring force to center the photolithographic reticle during the levitation.
4 more elements
Dependencies are inferred from the claim text.